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I'm intending to make changes to the
Troitzky line article.
I think the changes are necessary on the grounds of accuracy and clarity.
For background see the discussions Draws on and behind the Troitsky line and Troitsky line.
The current statement of the Troitzky line rule is
For the position with White to move, Troitsky established that if a black pawn is securely blockaded (by one of the white knights) on a square no further forward than the line a4–b6–c5–d4–e4–f5–g6–h4, then White can win the resulting endgame (and similarly in reverse for Black), no matter where the other pieces are placed.
(I added the word "securely" myself, because I assumed from the discussion in Draws on and behind the Troitsky line, that Bubba73 had intended the addition, but omitted it by oversight.)
The drawn position C' shown is a clear exception to the statement following the words, "For the position with White to move, Troitsky established that", rendering the complete statement incorrect.
Note that because of the phrase, "with White to move", positions A and B2 must be taken after Black's first move to count as candidate exceptions. I think the phrase is redundant and would like to find a source that doesn't include it.
The statement of the Troitzky line rule is also unclear, because the phrase "securely blockaded" is not defined.
I have been soliciting the views of chess players on whether the current wording is adequate to cover various drawn positions. The response so far is unanimously that the wording needs to be changed to cover each of the positions, except that Bubba73, so far as I understand, would regard the wording as OK in respect of at least position A shown, possibly also position B2.
The reason for Bubba73's viewpoint hinges on the meaning of the phrase "securely blockaded". I have discovered that different people have different opinions on this.
I think in view of the ambiguity the phrase needs further definition. The form of such a definition would also determine if exceptions of the type I show here run to millions or just thousands.
The Troitzky line rule is given without any attribution. I think it needs to be a cited reference. Further explanation or definition of the phrase "securely blockaded", should this occur in the citation, needs to be taken from the same source, otherwise, in view of the ambiguity, it could express something different from what the author intended.
I think the best source would be from the originator of the rule. (See subsequent questions.)
If the cited source doesn't define the phrase "securely blockaded" then I think some comment needs to be included about what the likely intention was. So far I have come across five views of what the term means:
(1) The knight stands on the square immediately in front of the pawn and is not en prise.
(2) The knight stands on the square immediately in front of the pawn and is directly defended by another white piece.
(3) The knight stands on the square immediately in front of the pawn and either the black king can be prevented from attacking the blockading knight or the knight can be directly defended if it is attacked, without, in the process, allowing the black king to capture the remaining knight or fork both knights in such a way that one can be captured on the subsequent move.
(4) Bubba73's meaning, which is, I believe, strictly between (3) and, "The knight stands on the square immediately in front of the pawn and all lines of play for black lead to a loss". ( Bubba73 has dropped out of the conversation and referred me here, so my apologies to Bubba73 if this is a misrepresentation.)
(5) The knight stands on a square forward of the pawn on the same file, the square behind the knight being understood as the point at which the pawn is blockaded, and either the black king can be prevented from attacking the blockading knight or the knight can be directly defended if it is attacked, without, in the process, allowing the black king to capture the remaining knight or fork both knights in such a way that one can be captured on the subsequent move.
The last of these was my own understanding until I started the discussion. I now find that it is incorrect in terms of standard chess terminology. I've included it because I suspect this was what Troitsky intended.
I would say that (1) cannot be the intended meaning in this case because there are then very many obvious exceptions.
I think (2) can also be discounted, because White would often not want to directly defend the blockading knight. For example C is won for White, but he draws if he directly defends the blockading knight.
I would expect (3) to be the majority understanding among readers without any further explanation in the text. With this definition all the drawn positions shown here would be exceptions.
Meaning (4) with appropriate formulation could possibly encompass positions A and B2, but a formulation would be difficult, and no reasonable formulation could encompass C', so is probably not worth while. Some exceptions would have to be noted in any case.
Meaning (5) would possibly be best if there were any reference for it. (I've previously understood "blocked" and "blockaded" in an English sense, i.e. if you can't immediately move where you want to go because there's something in the way, you're blocked, whereas if there's a blockade at the end of your cul-de-sac, you're blockaded even if you live at the other end of the cul-de-sac. Standard chess usage, if I now understand correctly, makes no distinction in the case of individual pawns and each implies there is a piece immediately in front of the pawn.)
I'm lacking sources, so I'm hoping someone can assist. At the moment I have only ( Averbakh & Chekhover 1977) relating to the two knights v pawn ending and it doesn't mention the Troitsky line. All the related internet references I can find are either verbatim copies of the Wikipaedia article (in the form prior to the recent changes) or links back to it. I've ordered ( Troitzky 1937) but it could be a month before it arrives.
In the meantime, it would be useful if anyone could answer any of the following questions.
(a) Did Troitzky propound the Troitzky line rule, or was this someone else based on Troitzky's analysis. ALREADY ANSWERED BY Bubba73
(b) If the answer to (a) is "someone else", who, and is there an available reference? NO LONGER RELEVANT
(c) If the answer to (a) is yes, is the rule to be found in ( Troitzky 1937) ? If not, where? I THINK ANSWERED AS YES BY CHESS CAFE ARTICLE
(d) Does anyone know of a source for the Troitzky line rule that implicitly or explicitly uses meaning (5) of the term "securely blockaded"?
(e) Can anyone provide a citation and the corresponding text for the Troitzky line rule? I believe, from what Bubba73 says that both ( Fine 1941) and ( Müller & Lamprecht 2001) should contain such. (A reference authored by Troitzky would be preferred.) ALREADY ANSWERED BY Bubba73 BUT (f) NOT AVAILABLE FROM SOURCE GIVEN
(f) Assuming the answer to (e) is yes, is there a definition or succinct explanation of "securely blockaded" or whatever equivalent is used? Can this text also be posted, please, if so?
(g) If I can find no source with a definition/explanation of "securely blockaded", which of (1)-(5) do you think should be the suggested meaning inserted in the article, or should it be something different from all of these?
I will post a draft when I have more information.
Martin Rattigan ( talk) 18:58, 14 June 2015 (UTC)
Fine and Benko, page 99, say "White wins if the pawn cannot cross the line." Bubba73 You talkin' to me? 02:27, 15 June 2015 (UTC)
Bubba73's contributions have already answered about half of the questions (a)-(e) I posed above (see capitalized comments following the questions). I'm hoping the remainder will be answered in ( Troitzky 1937) , which I expect to receive in about five weeks, so I think the discussion is probably best left dormant until then, but feel free to contribute if you think it will be useful. Martin Rattigan ( talk) 13:19, 16 June 2015 (UTC)
In the meantime, I have invested in the Kindle version of M&L FCE and confirmed that there is no further definition of "securely blockaded".
However the M&L statement includes the phrase "no matter where the kings are" but omits any reference to the knights. It is then possible that the intended meaning of the phrase "securely blockaded" in M&L is none of (1)-(5) I suggested above, but a new one viz:
(2 – ) A knight stands on the square immediately in front of the pawn and is directly defended by the other knight.
With this meaning the statement in M&L is correct (to the best of my knowledge).
I think that it would be clearer to give definition (2 – ) explicitly (both in Wikipedia and in M&L), since the reasons I give for inferring it are somewhat tenuous.
I am attempting to contact Dr. Müller for confirmation, but so far without any progress. Can anyone advise me how I might establish contact with either author?
I will wait a week or so for possible contradictory comments, then (if there are none) prepare a draft amendment.
Martin Rattigan ( talk) 12:51, 18 June 2015 (UTC)
Meaning (4) with appropriate formulation could possibly encompass positions A and B2, but a formulation would be difficult, and no reasonable formulation could encompass C', so is probably not worth while. Some exceptions would have to be noted in any case.
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Bubba, you say above
I think if the pawn is "securely blocked" then you're not forced to un-block it. Similarly, if you have to give up a knight, it is no longer a two knights versus pawn endgame.
I think by this you intend to imply that the wording in the Troitzky line section is acceptable as it stands. Forgive me if I'm wrong.
If this is what you intended then I think your position is untenable.
If you consider the position E to the right, I would say this is a standard win under the Troitzky line rule as stated. However, to win white is forced to both unblock the h4 pawn and offer Black one of his knights.
According to what you say, it would seem you neither consider this position to be a two knights v pawn ending nor consider the h4 pawn to be securely blocked.
I don't think you could possibly expect readers of the article to concur.
Can we agree that the section is in need of revision?
Martin Rattigan ( talk) 19:52, 19 June 2015 (UTC)
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The draws are also exceptions to the second Troitzky line rule (except that B2 would need to be moved two squares toward the queen side; B3 right). This section therefore also needs to be changed. References for a revised version could be problematic unless the result has been updated with the advent of the Syzygy DTM50 EGTBs.
Can anybody with a set of Syzygy EGTBs confirm that the line is in fact valid. (It would have been difficult and possibly prone to error to establish the result with the Nalimov DTM EGTBs.) I will download the Syzygy EGTBs myself and check, but I'm quite slow at that sort of thing and busy with other things at the moment.
If it isn't valid then it might be better to drop the section.
Martin Rattigan ( talk) 19:17, 21 June 2015 (UTC)
Dr. Muller's article here strongly suggests that his interpretation of "securely blockaded" is not (2 – ). This means I can't just cite M&L and give meaning (2 – ) as the definition of the phrase. But with luck I can cite directly from ( Troitzky 1937) - this is the source given in the article. (I think question (c) is answered in the affirmative.)
Martin Rattigan ( talk) 21:37, 21 June 2015 (UTC)
For info, I wrote, "I have been soliciting the views of chess players on whether the current wording is adequate to cover various drawn positions. The response so far is unanimously that the wording needs to be changed". I now have two opposing views (not including Bubba and Cobblet, who I hope to convince; these from here) so it's standing at 6 in favour of change, 2 against to date. Martin Rattigan ( talk) 23:59, 22 June 2015 (UTC)
Dr. Müller has responded to my email to Chess Café. He wrote:
You can use the quote from FCE. You can of course also add your definition of "securely blockaded" as the blockading knight is protected by the other knight. In FCE Frank Lamprecht and I indeed used "no matter, where the kings are" to deal with this problem. Of course it would be best, if an original quote from Troitzky can be found and used.
Martin Rattigan ( talk) 09:16, 23 June 2015 (UTC)
Since I proposed to produce a draft ( #Draft proposed), objections to changing the current wording have been raised by Bubba ( #Bubba's objection) and Cobblet ( #Cobblet's objection). I don't accept either of the objections as valid. I will deal with each in detail.
A. Bubba's objection.
B. Cobblet's objection.
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So you're telling me that in position H, it is "obviously" correct to say that White's knight guards h2, because White can achieve this by force in eight moves. To me these are not equivalent statements – the second part is not obvious to all but the most sophisticated of endgame players. Your interpretation of the word "guards" is non-standard. Cobblet ( talk) 04:06, 28 June 2015 (UTC)
I have removed the final sentence from the second paragraph of the "Troitzky line" section which was incorrect and unsourced and replaced it with the Rabinovich quote Bubba provided earlier, which is similar but correct. I have also inserted two "citation needed" flags pending deletion or replacement of sentences preceding the flags. The first sentence, "Therefore the ending is more of theoretical than practical interest.", is unsourced and appears to express the author's own view. The other sentences (starting the subsection "Pawn beyond the Troitzky line"), "If a pawn is beyond the Troitsky line, the result usually depends on the location of the defending king. Usually there is a "drawing area" and a "losing area" for the defending king, which was also analyzed by Troitsky.", are either unsourced, or, if the source is meant to be M&L as inserted at the end of the paragraph, both innaccurate and taken out of context rendering it grossly incorrect. — Preceding unsigned comment added by 80.2.119.0 ( talk) 09:25, 1 July 2015 (UTC)
I have deleted the sentences referred to. Martin Rattigan ( talk) 22:34, 7 July 2015 (UTC)
Unless further objections are raised, or objections are raised to the above reasons for dismissing the objections so far raised, I now plan to produce a draft after I have received ( Troitzky 1937) . I expect this to be ready near the end of July.
Martin Rattigan ( talk) 20:53, 26 June 2015 (UTC)
I have just received ( Troitzky 1937) . Although it looks as if there is enough analysis to support a carefully constructed version of the Troitsky line rule (I haven't had time to check this) there appears to be no explicit mention of the Troitsky line or the rule. Moreover it wouldn't be feasible to construct a readily comprehensible version using only direct quotes without forming a conclusion from the quotes that is not explicitly contained in the original. Troitsky's version of the rule (assuming it exists) could well be from the same source as Rabinovich quotes, since the line was there explicitly mentioned. But from the paragraph given this could be ( Troitzky 1937) if Rabinovich first included the paragraph in the 1938 edition, because he says, "Troitsky showed ..." rather than "Troitsky stated ...".
For the time being I will produce a version using ( Müller & Lamprecht 2001). The reader will have to do without an explicit translation of "securely blockaded" (courtesy of Cobblet and the Wiki legal system), but the source contains further explanation which I will also include, so he should be left in no doubt.
This should be ready in a week or so. Martin Rattigan ( talk) 23:24, 7 July 2015 (UTC)
_______________________________________________________________________________________________________________________ (this line not for inclusion)
/*==Troitzky line==*/ Troitzky line
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1. Kh4 Kg2 2. Kg4 Kg1 3. Kh3 Kh1 4. Ng3+ Kg1 5. Nf3#
The pawn does not move; it assists mate by blocking the king's escape.
Whilst two knights cannot force checkmate (with the help of their king) against a lone king, a decrease in material advantage allowing the defending king to have a pawn can actually cause his demise. The reason that checkmate can be forced is that the pawn gives the defender a piece to move and deprives him of a stalemate defense ( Müller & Lamprecht 2001:19–20). Another reason is that the pawn can block its own king's path without necessarily moving (e.g. Kling & Horwitz position right).
The Troitzky (or Troitsky) line (or Troitzky position) is a key motif in chess endgame theory in the rare but theoretically interesting ending of two knights versus a pawn.
The line, assuming White has the two knights and Black the pawn, is shown left.
The Russian theoretician Troitsky made a detailed study of this endgame and discovered the following rule:
If the pawn is securely blockaded by a white knight no further down than the line, then Black loses, no matter where the kings are.
— Karsten Müller and Frank Lamprecht, Fundamental Chess Endings 2001
An example of the application of this rule is given in the diagram Müller and Lamprecht right; "... the position would be lost no matter where the kings are". ( Müller & Lamprecht 2001)
However, the checkmate procedure is difficult and long. In fact, it can require up to 115 moves by White, so in competition often a draw by the fifty-move rule will occur first (but see this article and Second Troitzky line section for the zone where the win can be forced within fifty moves).
Troitsky showed that "on any placement of the black king, White undoubtedly wins only against black pawns standing on [The Troitzky line] and above" ( Rabinovich 1927:88) .
John Nunn analyzed the endgame of two knights versus a pawn with an endgame tablebase and stated that "the analysis of Troitsky and others is astonishingly accurate" ( Nunn 1995:265) .
Even when the position is a theoretical win, it is very complicated and difficult to play correctly. Even grandmasters fail to win it. Andor Lilienthal failed to win it twice in a six-year period, see Norman vs. Lilienthal and Smyslov vs. Lilienthal. But a fine win is in a game by Seitz, see Znosko-Borovsky vs. Seitz ( Giddins 2012:26) .
Two knights versus pawn is sometimes called the "Halley's Comet" endgame. [1]
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notes
Martin Rattigan ( talk) 17:33, 14 July 2015 (UTC)
Is the ratings bot not working or is there a formatting problem with some articles? For example, at articles such as Watu Kobese, the rating is not automatically being filled in. Greenman ( talk) 17:47, 10 July 2015 (UTC)
I'm not happy with all these new categories at all, e.g. Category:Women's chess players. MaxBrowne ( talk) 15:42, 18 August 2015 (UTC)
I can answer the question "Why we need the female categories?". There are more and more players in many categories where are men and women together. I want find women only and this isn't easy. I waste time for searching a few women among hundreds of men. I think "adopt the poker categories" is good idea ( Category:Women's chess players -> Category:Female chess players). Examples:
I think first part of separating can be doing by bot with using category Category:Chess woman grandmasters Mircea ( talk) 06:49, 20 August 2015 (UTC)
Have a look. Just created it. Probabaly needs more sources. - Koppapa ( talk) 16:45, 4 September 2015 (UTC)
The Elo in the infoboxes unfortunately is still from July, i.e. 2 months old. Example: Ralf Åkesson. Who is updating this? Best regards, -- Gereon K. ( talk) 16:15, 10 September 2015 (UTC)
How does everyone feel about the addition of World Cup results tables? This has been done over numerous articles in the past couple of days and I'm not keen on them, seeing as they duplicate information which should already be in the main section as prose. I'm also concerned that the average reader will not understand it. The editor has argued that the table is done in other sports. I suggested going to Talk but they have instead continued editing pages in this way. Jkmaskell ( talk) 20:28, 16 September 2015 (UTC)
I think the lack of documentation of the South American chess scene in general may be the issue here, rather than his inherent lack of notability. He was a damn good player - check out his games for proof, look at his coolness under fire against Panno for example. He was probably stronger than many European players who have articles, and apparently was renowned as a coach too. But chess literature, like wikipedia, tends to centre on the Anglosphere and Europe. MaxBrowne ( talk) 07:52, 28 October 2015 (UTC)
Chess gets short shrift, it seems to me, in many articles not principally about chess where it deserves a sub-section, or a mention. I thought the page Knockout tournament was one such, and I wanted to call attention to it here, but couldn't find the right place to do so.
I looked at all the sections on the Project page for where to put my request, but there wasn't one, so maybe we need a new area on the Project page for "articles that are principally about something else, but have a section that touches on chess, or has a section that ought to touch on chess, but doesn't, or needs improvement." Well, the section needs a shorter name, how 'bout, Non-chess articles needing improvement or some such.
In particular, Knockout tournament is a REDIRECT to Single-elimination tournament, which mentions chess once, in passing. In my view, there ought to be a section or sub-section there, with a brief overview on how chess tournaments work since the 1990s, along with a link to some chess page for more detail. That specific suggestion is perhaps a topic for a new section on Talk:Single-elimination tournament and I may or may not add it, if I have time, but the point here is, Where on the WikiProject Chess should one call attention to a situation like this so interested Project members are aware of it? I think there's isn't one, and that we need such a section.
If somebody creates a section for it, please ping me, or just move my request there. This would have the benefit of generating more inlinks to chess project articles from articles in sports, game theory, history, bios of individuals not known primarily for chess, computation and artificial intelligence, mathematical puzzles, athletic training, broadcast sports and television, social and club activities, and other areas; with a hopefully salutary effect on page views of chess articles. Mathglot ( talk) 02:54, 30 October 2015 (UTC)
Hi all, I've started the 2015 in chess article. I'd appreciate any help with adding tournaments, referencing tournaments, and the like! Thanks, /wia /tlk /cntrb 21:12, 2 November 2015 (UTC)
I'm already on 3R so I could get in trouble if I engage any further. Defining chess as a "sport" in the opening sentence of the main chess article is clear POV pushing. I've tried to explain on the talk page but he just keeps reverting. Defining chess as a "mind sport" as another editor wants isn't much better - this is not a familiar term to the average reader. The article was fine just how it was, defining it as a "board game" in the opening sentence and noting that the IOC recognizes it as a sport a bit later on. This fairly reflects the prominence of the "chess is a sport" argument.
You wouldn't go to the Shogi article and expect to read "Shogi is a Japanese sport" or even "Shogi is a Japanese mind sport" in the opening paragraph, but Shogi is highly organized and has serious competitions, just as chess does. MaxBrowne ( talk) 22:43, 3 November 2015 (UTC)
I'm a bit on the fence with this one. I removed the PROD to generate a discussion but I'm not really sure there's much to say about the topic. Maybe a description and illustration of chess fonts, like the old fashioned ornate font used by British publishers like Bell until the 60s, the Batsford-style font from the 60s-90s, and the modern fonts? Can't find much material on this topic on line either. MaxBrowne ( talk) 01:53, 1 December 2015 (UTC)
This is a new article created by User:Dino for the sequence 1.Nf3 d5 2.g3. The implication of the title is that there's a variation of the Réti Opening which is known as the King's Indian Attack. If one defines the Réti as simply the move 1.Nf3, then this is not unreasonable, but we still shouldn't have separate articles on the KIA and the "KIA variation of the Réti". It also remains common to reserve the term "Réti" for systems involving a quick c2-c4 hitting a pawn on d5, and the KIA for systems that do without this move (if an early central break is played it's usually e2-e4). Under this convention, the Réti and KIA are different openings – one is not a variation of the other. I thought this was already explained in our articles on the two terms as well as in Zukertort Opening. I suggest redirecting this article to King's Indian Attack. Cobblet ( talk) 09:44, 19 December 2015 (UTC)
---
I too wondered of the similarity. But kept finding Internet references to the "Réti Opening, King's Indian Attack," plus a few books about it, as [1].
dino ( talk) 22:43, 19 December 2015 (UTC)
Yochanan Afek has apparently reported the death of Zvulon Gofshtein on Facebook. I'm looking for an official source for the information but can't find one. Maybe someone who can read Hebrew will have better luck? Cobblet ( talk) 03:35, 26 December 2015 (UTC)
זבולון גופשטיין שחמט
Could use a third party to weigh in at Talk:United States Chess Federation#"US Chess". I'm at 3RR. IP seems intent to edit war over the matter and hasn't yet used the talk page. It's possible I'm in the wrong here, but I don't think a common acronym should be dispatched with universally because an organization decides it's changing its marketing strategy. — Rhododendrites talk \\ 05:31, 10 January 2016 (UTC)
I've started a thread at Talk:Alexey Troitsky#Troitsky vs Troitzky in the article that project members may be interested in given the amount of attention that went into /Archive 31#Proposed changes to the Troitzky line article. -- Marc Kupper| talk 09:22, 4 February 2016 (UTC)
This article looks totally redundant to me. It started out as a redirect, then became a DAB page, then somehow it became an article. It has no coherent theme and there is nothing in the article that isn't covered better elsewhere in wikipedia. MaxBrowne ( talk) 23:25, 5 February 2016 (UTC)
Created articles for the next two women's editions 2016 (knock-out), 2017. I won't move the 2016 match article for now, guess it's fine now. Suggestions to improve? - Koppapa ( talk) 16:15, 14 February 2016 (UTC)
There is a widely debated topic on chess history, it is not clear whether it is based on facts or rumours/speculations. the topic is: "Alekhine-Capablanca world championship rematch." Some believe Alekhine avoided Capablanca and some believe contrary, ALekhine gave him a chance but Capa did not use it. can wikipedia enlighten all of us on this matter? p.s: I am not good at wikipedia, I cant add references and e.t.c. -- Sir artur ( talk) 19:53, 5 February 2016 (UTC)
Looking at the cleanup listings for the WikiProject and coming across the incomplete list section which as you would expect contains a lot of national championships. British Chess Championship is on the list but looking at the article I don't see any missing events. Given we can't add this years yet because it hasn't happened is there really a need for it to be tagged? Strictly speaking it should have a maintenance tag on there saying it is complete as of whenever, but then it'll appear in the "potentially dated" category. Jkmaskell ( talk) 18:00, 6 April 2016 (UTC)
This draft is at AFC for review, we need some advice about its notability and whether the sourcing is good. Please post your comments to the draft's talk page. Roger (Dodger67) ( talk) 15:42, 13 April 2016 (UTC)
A discussion started in template talk page, because I'm testing a new version in order to fix some displaying problems of current diagram. Please, join. -- Francois-Pier ( talk) 09:19, 15 April 2016 (UTC)
The recent edit and reversion at Two Knights Defense has got me thinking. The annotation symbols "!?" and "?!" are inherently subjective and reflect the opinion of the annotator; as such is it ever appropriate to use them in a wikipedia article? Maybe Harding says 4...Nxe4 is "?!", but other writers might give it a "!?". There's no particular reason to prefer Harding over Estrin or Beliavsky or the numerous others who have written about the opening. Maybe we should take the Hübner approach and award only question marks to objectively bad moves, leaving the "!"s and "!?"s and "?!"s to writers who are under no obligation to be neutral? MaxBrowne ( talk) 03:44, 12 April 2016 (UTC)
I added the 4...Nxe4?! material more than 3 yrs ago. Since it was difficult see who was quoting whom, I made some adjustments (added sources for Gligoric, Korn; everything not from Harding/Botterill is sourced individually now, perhaps that improves). Probably the 5.Nxf7? line can be eliminated as too detailed (overkill). ( Cobblet, maybe the entire 4...Nxe4 line is just a footnote/overkill, too!? If so feel free to delete.) Almost all the Harding/Botterill material after 5.Bxf7+ is also found in ECO C2 (1981, Gligoric), and that material has been carried over without change, to ECO C3 (1997, Matulovic). Of course anyone w/ more recent analysis should go ahead and improve the article. (Ya gotta start somewhere, right!? [Or the line can be deleted, as above.]) Cheers, IHTS ( talk) 07:36, 13 April 2016 (UTC)
Addendum: Oh! I see the point re "WP's voice", I think: 4...Nxe4?!, unattributed, was in the TOC (which might convey WP's voice). Instead of adding attribution to the TOC, I removed the symbol, so now only the article body has it. (If still unclear the symbol is attributed to Harding/Botterill, I can copyedit some more, just let know.) BTW, Gligoric also gives 4...Nxe4?!, and as mentioned Matulovic copies that, but Korn gives 4...Nxe4?) IHTS ( talk) 07:57, 13 April 2016 (UTC)
Anyway I've trimmed out the 8.d5 line per Maric's 9...Kg8! discovery. And I've re-placed couple supporting refs for better clarity. (My only src for 5.Nxf7? line is Harding/Botterill book. Everything after 7.Nc3! is contained in ECO C *2* and *3*, except the attribution of 7.Nc3! to Lopukhin, the attribution of 10.Bg8! to Estrin, and the subvar 8...e4 9.f3!, and those three things I'd found only in Harding/Botterill. [How much of that analysis is Lopukhin's I don't know; re attribution what I did was draw on Gligoric's assignment re C57 in ECO C *2*, p. 247.]) IHTS ( talk) 09:08, 14 April 2016 (UTC)
![]() | This is an archive of past discussions. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page. |
Archive 25 | ← | Archive 29 | Archive 30 | Archive 31 | Archive 32 | Archive 33 | → | Archive 35 |
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I'm intending to make changes to the
Troitzky line article.
I think the changes are necessary on the grounds of accuracy and clarity.
For background see the discussions Draws on and behind the Troitsky line and Troitsky line.
The current statement of the Troitzky line rule is
For the position with White to move, Troitsky established that if a black pawn is securely blockaded (by one of the white knights) on a square no further forward than the line a4–b6–c5–d4–e4–f5–g6–h4, then White can win the resulting endgame (and similarly in reverse for Black), no matter where the other pieces are placed.
(I added the word "securely" myself, because I assumed from the discussion in Draws on and behind the Troitsky line, that Bubba73 had intended the addition, but omitted it by oversight.)
The drawn position C' shown is a clear exception to the statement following the words, "For the position with White to move, Troitsky established that", rendering the complete statement incorrect.
Note that because of the phrase, "with White to move", positions A and B2 must be taken after Black's first move to count as candidate exceptions. I think the phrase is redundant and would like to find a source that doesn't include it.
The statement of the Troitzky line rule is also unclear, because the phrase "securely blockaded" is not defined.
I have been soliciting the views of chess players on whether the current wording is adequate to cover various drawn positions. The response so far is unanimously that the wording needs to be changed to cover each of the positions, except that Bubba73, so far as I understand, would regard the wording as OK in respect of at least position A shown, possibly also position B2.
The reason for Bubba73's viewpoint hinges on the meaning of the phrase "securely blockaded". I have discovered that different people have different opinions on this.
I think in view of the ambiguity the phrase needs further definition. The form of such a definition would also determine if exceptions of the type I show here run to millions or just thousands.
The Troitzky line rule is given without any attribution. I think it needs to be a cited reference. Further explanation or definition of the phrase "securely blockaded", should this occur in the citation, needs to be taken from the same source, otherwise, in view of the ambiguity, it could express something different from what the author intended.
I think the best source would be from the originator of the rule. (See subsequent questions.)
If the cited source doesn't define the phrase "securely blockaded" then I think some comment needs to be included about what the likely intention was. So far I have come across five views of what the term means:
(1) The knight stands on the square immediately in front of the pawn and is not en prise.
(2) The knight stands on the square immediately in front of the pawn and is directly defended by another white piece.
(3) The knight stands on the square immediately in front of the pawn and either the black king can be prevented from attacking the blockading knight or the knight can be directly defended if it is attacked, without, in the process, allowing the black king to capture the remaining knight or fork both knights in such a way that one can be captured on the subsequent move.
(4) Bubba73's meaning, which is, I believe, strictly between (3) and, "The knight stands on the square immediately in front of the pawn and all lines of play for black lead to a loss". ( Bubba73 has dropped out of the conversation and referred me here, so my apologies to Bubba73 if this is a misrepresentation.)
(5) The knight stands on a square forward of the pawn on the same file, the square behind the knight being understood as the point at which the pawn is blockaded, and either the black king can be prevented from attacking the blockading knight or the knight can be directly defended if it is attacked, without, in the process, allowing the black king to capture the remaining knight or fork both knights in such a way that one can be captured on the subsequent move.
The last of these was my own understanding until I started the discussion. I now find that it is incorrect in terms of standard chess terminology. I've included it because I suspect this was what Troitsky intended.
I would say that (1) cannot be the intended meaning in this case because there are then very many obvious exceptions.
I think (2) can also be discounted, because White would often not want to directly defend the blockading knight. For example C is won for White, but he draws if he directly defends the blockading knight.
I would expect (3) to be the majority understanding among readers without any further explanation in the text. With this definition all the drawn positions shown here would be exceptions.
Meaning (4) with appropriate formulation could possibly encompass positions A and B2, but a formulation would be difficult, and no reasonable formulation could encompass C', so is probably not worth while. Some exceptions would have to be noted in any case.
Meaning (5) would possibly be best if there were any reference for it. (I've previously understood "blocked" and "blockaded" in an English sense, i.e. if you can't immediately move where you want to go because there's something in the way, you're blocked, whereas if there's a blockade at the end of your cul-de-sac, you're blockaded even if you live at the other end of the cul-de-sac. Standard chess usage, if I now understand correctly, makes no distinction in the case of individual pawns and each implies there is a piece immediately in front of the pawn.)
I'm lacking sources, so I'm hoping someone can assist. At the moment I have only ( Averbakh & Chekhover 1977) relating to the two knights v pawn ending and it doesn't mention the Troitsky line. All the related internet references I can find are either verbatim copies of the Wikipaedia article (in the form prior to the recent changes) or links back to it. I've ordered ( Troitzky 1937) but it could be a month before it arrives.
In the meantime, it would be useful if anyone could answer any of the following questions.
(a) Did Troitzky propound the Troitzky line rule, or was this someone else based on Troitzky's analysis. ALREADY ANSWERED BY Bubba73
(b) If the answer to (a) is "someone else", who, and is there an available reference? NO LONGER RELEVANT
(c) If the answer to (a) is yes, is the rule to be found in ( Troitzky 1937) ? If not, where? I THINK ANSWERED AS YES BY CHESS CAFE ARTICLE
(d) Does anyone know of a source for the Troitzky line rule that implicitly or explicitly uses meaning (5) of the term "securely blockaded"?
(e) Can anyone provide a citation and the corresponding text for the Troitzky line rule? I believe, from what Bubba73 says that both ( Fine 1941) and ( Müller & Lamprecht 2001) should contain such. (A reference authored by Troitzky would be preferred.) ALREADY ANSWERED BY Bubba73 BUT (f) NOT AVAILABLE FROM SOURCE GIVEN
(f) Assuming the answer to (e) is yes, is there a definition or succinct explanation of "securely blockaded" or whatever equivalent is used? Can this text also be posted, please, if so?
(g) If I can find no source with a definition/explanation of "securely blockaded", which of (1)-(5) do you think should be the suggested meaning inserted in the article, or should it be something different from all of these?
I will post a draft when I have more information.
Martin Rattigan ( talk) 18:58, 14 June 2015 (UTC)
Fine and Benko, page 99, say "White wins if the pawn cannot cross the line." Bubba73 You talkin' to me? 02:27, 15 June 2015 (UTC)
Bubba73's contributions have already answered about half of the questions (a)-(e) I posed above (see capitalized comments following the questions). I'm hoping the remainder will be answered in ( Troitzky 1937) , which I expect to receive in about five weeks, so I think the discussion is probably best left dormant until then, but feel free to contribute if you think it will be useful. Martin Rattigan ( talk) 13:19, 16 June 2015 (UTC)
In the meantime, I have invested in the Kindle version of M&L FCE and confirmed that there is no further definition of "securely blockaded".
However the M&L statement includes the phrase "no matter where the kings are" but omits any reference to the knights. It is then possible that the intended meaning of the phrase "securely blockaded" in M&L is none of (1)-(5) I suggested above, but a new one viz:
(2 – ) A knight stands on the square immediately in front of the pawn and is directly defended by the other knight.
With this meaning the statement in M&L is correct (to the best of my knowledge).
I think that it would be clearer to give definition (2 – ) explicitly (both in Wikipedia and in M&L), since the reasons I give for inferring it are somewhat tenuous.
I am attempting to contact Dr. Müller for confirmation, but so far without any progress. Can anyone advise me how I might establish contact with either author?
I will wait a week or so for possible contradictory comments, then (if there are none) prepare a draft amendment.
Martin Rattigan ( talk) 12:51, 18 June 2015 (UTC)
Meaning (4) with appropriate formulation could possibly encompass positions A and B2, but a formulation would be difficult, and no reasonable formulation could encompass C', so is probably not worth while. Some exceptions would have to be noted in any case.
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Bubba, you say above
I think if the pawn is "securely blocked" then you're not forced to un-block it. Similarly, if you have to give up a knight, it is no longer a two knights versus pawn endgame.
I think by this you intend to imply that the wording in the Troitzky line section is acceptable as it stands. Forgive me if I'm wrong.
If this is what you intended then I think your position is untenable.
If you consider the position E to the right, I would say this is a standard win under the Troitzky line rule as stated. However, to win white is forced to both unblock the h4 pawn and offer Black one of his knights.
According to what you say, it would seem you neither consider this position to be a two knights v pawn ending nor consider the h4 pawn to be securely blocked.
I don't think you could possibly expect readers of the article to concur.
Can we agree that the section is in need of revision?
Martin Rattigan ( talk) 19:52, 19 June 2015 (UTC)
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The draws are also exceptions to the second Troitzky line rule (except that B2 would need to be moved two squares toward the queen side; B3 right). This section therefore also needs to be changed. References for a revised version could be problematic unless the result has been updated with the advent of the Syzygy DTM50 EGTBs.
Can anybody with a set of Syzygy EGTBs confirm that the line is in fact valid. (It would have been difficult and possibly prone to error to establish the result with the Nalimov DTM EGTBs.) I will download the Syzygy EGTBs myself and check, but I'm quite slow at that sort of thing and busy with other things at the moment.
If it isn't valid then it might be better to drop the section.
Martin Rattigan ( talk) 19:17, 21 June 2015 (UTC)
Dr. Muller's article here strongly suggests that his interpretation of "securely blockaded" is not (2 – ). This means I can't just cite M&L and give meaning (2 – ) as the definition of the phrase. But with luck I can cite directly from ( Troitzky 1937) - this is the source given in the article. (I think question (c) is answered in the affirmative.)
Martin Rattigan ( talk) 21:37, 21 June 2015 (UTC)
For info, I wrote, "I have been soliciting the views of chess players on whether the current wording is adequate to cover various drawn positions. The response so far is unanimously that the wording needs to be changed". I now have two opposing views (not including Bubba and Cobblet, who I hope to convince; these from here) so it's standing at 6 in favour of change, 2 against to date. Martin Rattigan ( talk) 23:59, 22 June 2015 (UTC)
Dr. Müller has responded to my email to Chess Café. He wrote:
You can use the quote from FCE. You can of course also add your definition of "securely blockaded" as the blockading knight is protected by the other knight. In FCE Frank Lamprecht and I indeed used "no matter, where the kings are" to deal with this problem. Of course it would be best, if an original quote from Troitzky can be found and used.
Martin Rattigan ( talk) 09:16, 23 June 2015 (UTC)
Since I proposed to produce a draft ( #Draft proposed), objections to changing the current wording have been raised by Bubba ( #Bubba's objection) and Cobblet ( #Cobblet's objection). I don't accept either of the objections as valid. I will deal with each in detail.
A. Bubba's objection.
B. Cobblet's objection.
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So you're telling me that in position H, it is "obviously" correct to say that White's knight guards h2, because White can achieve this by force in eight moves. To me these are not equivalent statements – the second part is not obvious to all but the most sophisticated of endgame players. Your interpretation of the word "guards" is non-standard. Cobblet ( talk) 04:06, 28 June 2015 (UTC)
I have removed the final sentence from the second paragraph of the "Troitzky line" section which was incorrect and unsourced and replaced it with the Rabinovich quote Bubba provided earlier, which is similar but correct. I have also inserted two "citation needed" flags pending deletion or replacement of sentences preceding the flags. The first sentence, "Therefore the ending is more of theoretical than practical interest.", is unsourced and appears to express the author's own view. The other sentences (starting the subsection "Pawn beyond the Troitzky line"), "If a pawn is beyond the Troitsky line, the result usually depends on the location of the defending king. Usually there is a "drawing area" and a "losing area" for the defending king, which was also analyzed by Troitsky.", are either unsourced, or, if the source is meant to be M&L as inserted at the end of the paragraph, both innaccurate and taken out of context rendering it grossly incorrect. — Preceding unsigned comment added by 80.2.119.0 ( talk) 09:25, 1 July 2015 (UTC)
I have deleted the sentences referred to. Martin Rattigan ( talk) 22:34, 7 July 2015 (UTC)
Unless further objections are raised, or objections are raised to the above reasons for dismissing the objections so far raised, I now plan to produce a draft after I have received ( Troitzky 1937) . I expect this to be ready near the end of July.
Martin Rattigan ( talk) 20:53, 26 June 2015 (UTC)
I have just received ( Troitzky 1937) . Although it looks as if there is enough analysis to support a carefully constructed version of the Troitsky line rule (I haven't had time to check this) there appears to be no explicit mention of the Troitsky line or the rule. Moreover it wouldn't be feasible to construct a readily comprehensible version using only direct quotes without forming a conclusion from the quotes that is not explicitly contained in the original. Troitsky's version of the rule (assuming it exists) could well be from the same source as Rabinovich quotes, since the line was there explicitly mentioned. But from the paragraph given this could be ( Troitzky 1937) if Rabinovich first included the paragraph in the 1938 edition, because he says, "Troitsky showed ..." rather than "Troitsky stated ...".
For the time being I will produce a version using ( Müller & Lamprecht 2001). The reader will have to do without an explicit translation of "securely blockaded" (courtesy of Cobblet and the Wiki legal system), but the source contains further explanation which I will also include, so he should be left in no doubt.
This should be ready in a week or so. Martin Rattigan ( talk) 23:24, 7 July 2015 (UTC)
_______________________________________________________________________________________________________________________ (this line not for inclusion)
/*==Troitzky line==*/ Troitzky line
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1. Kh4 Kg2 2. Kg4 Kg1 3. Kh3 Kh1 4. Ng3+ Kg1 5. Nf3#
The pawn does not move; it assists mate by blocking the king's escape.
Whilst two knights cannot force checkmate (with the help of their king) against a lone king, a decrease in material advantage allowing the defending king to have a pawn can actually cause his demise. The reason that checkmate can be forced is that the pawn gives the defender a piece to move and deprives him of a stalemate defense ( Müller & Lamprecht 2001:19–20). Another reason is that the pawn can block its own king's path without necessarily moving (e.g. Kling & Horwitz position right).
The Troitzky (or Troitsky) line (or Troitzky position) is a key motif in chess endgame theory in the rare but theoretically interesting ending of two knights versus a pawn.
The line, assuming White has the two knights and Black the pawn, is shown left.
The Russian theoretician Troitsky made a detailed study of this endgame and discovered the following rule:
If the pawn is securely blockaded by a white knight no further down than the line, then Black loses, no matter where the kings are.
— Karsten Müller and Frank Lamprecht, Fundamental Chess Endings 2001
An example of the application of this rule is given in the diagram Müller and Lamprecht right; "... the position would be lost no matter where the kings are". ( Müller & Lamprecht 2001)
However, the checkmate procedure is difficult and long. In fact, it can require up to 115 moves by White, so in competition often a draw by the fifty-move rule will occur first (but see this article and Second Troitzky line section for the zone where the win can be forced within fifty moves).
Troitsky showed that "on any placement of the black king, White undoubtedly wins only against black pawns standing on [The Troitzky line] and above" ( Rabinovich 1927:88) .
John Nunn analyzed the endgame of two knights versus a pawn with an endgame tablebase and stated that "the analysis of Troitsky and others is astonishingly accurate" ( Nunn 1995:265) .
Even when the position is a theoretical win, it is very complicated and difficult to play correctly. Even grandmasters fail to win it. Andor Lilienthal failed to win it twice in a six-year period, see Norman vs. Lilienthal and Smyslov vs. Lilienthal. But a fine win is in a game by Seitz, see Znosko-Borovsky vs. Seitz ( Giddins 2012:26) .
Two knights versus pawn is sometimes called the "Halley's Comet" endgame. [1]
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notes
Martin Rattigan ( talk) 17:33, 14 July 2015 (UTC)
Is the ratings bot not working or is there a formatting problem with some articles? For example, at articles such as Watu Kobese, the rating is not automatically being filled in. Greenman ( talk) 17:47, 10 July 2015 (UTC)
I'm not happy with all these new categories at all, e.g. Category:Women's chess players. MaxBrowne ( talk) 15:42, 18 August 2015 (UTC)
I can answer the question "Why we need the female categories?". There are more and more players in many categories where are men and women together. I want find women only and this isn't easy. I waste time for searching a few women among hundreds of men. I think "adopt the poker categories" is good idea ( Category:Women's chess players -> Category:Female chess players). Examples:
I think first part of separating can be doing by bot with using category Category:Chess woman grandmasters Mircea ( talk) 06:49, 20 August 2015 (UTC)
Have a look. Just created it. Probabaly needs more sources. - Koppapa ( talk) 16:45, 4 September 2015 (UTC)
The Elo in the infoboxes unfortunately is still from July, i.e. 2 months old. Example: Ralf Åkesson. Who is updating this? Best regards, -- Gereon K. ( talk) 16:15, 10 September 2015 (UTC)
How does everyone feel about the addition of World Cup results tables? This has been done over numerous articles in the past couple of days and I'm not keen on them, seeing as they duplicate information which should already be in the main section as prose. I'm also concerned that the average reader will not understand it. The editor has argued that the table is done in other sports. I suggested going to Talk but they have instead continued editing pages in this way. Jkmaskell ( talk) 20:28, 16 September 2015 (UTC)
I think the lack of documentation of the South American chess scene in general may be the issue here, rather than his inherent lack of notability. He was a damn good player - check out his games for proof, look at his coolness under fire against Panno for example. He was probably stronger than many European players who have articles, and apparently was renowned as a coach too. But chess literature, like wikipedia, tends to centre on the Anglosphere and Europe. MaxBrowne ( talk) 07:52, 28 October 2015 (UTC)
Chess gets short shrift, it seems to me, in many articles not principally about chess where it deserves a sub-section, or a mention. I thought the page Knockout tournament was one such, and I wanted to call attention to it here, but couldn't find the right place to do so.
I looked at all the sections on the Project page for where to put my request, but there wasn't one, so maybe we need a new area on the Project page for "articles that are principally about something else, but have a section that touches on chess, or has a section that ought to touch on chess, but doesn't, or needs improvement." Well, the section needs a shorter name, how 'bout, Non-chess articles needing improvement or some such.
In particular, Knockout tournament is a REDIRECT to Single-elimination tournament, which mentions chess once, in passing. In my view, there ought to be a section or sub-section there, with a brief overview on how chess tournaments work since the 1990s, along with a link to some chess page for more detail. That specific suggestion is perhaps a topic for a new section on Talk:Single-elimination tournament and I may or may not add it, if I have time, but the point here is, Where on the WikiProject Chess should one call attention to a situation like this so interested Project members are aware of it? I think there's isn't one, and that we need such a section.
If somebody creates a section for it, please ping me, or just move my request there. This would have the benefit of generating more inlinks to chess project articles from articles in sports, game theory, history, bios of individuals not known primarily for chess, computation and artificial intelligence, mathematical puzzles, athletic training, broadcast sports and television, social and club activities, and other areas; with a hopefully salutary effect on page views of chess articles. Mathglot ( talk) 02:54, 30 October 2015 (UTC)
Hi all, I've started the 2015 in chess article. I'd appreciate any help with adding tournaments, referencing tournaments, and the like! Thanks, /wia /tlk /cntrb 21:12, 2 November 2015 (UTC)
I'm already on 3R so I could get in trouble if I engage any further. Defining chess as a "sport" in the opening sentence of the main chess article is clear POV pushing. I've tried to explain on the talk page but he just keeps reverting. Defining chess as a "mind sport" as another editor wants isn't much better - this is not a familiar term to the average reader. The article was fine just how it was, defining it as a "board game" in the opening sentence and noting that the IOC recognizes it as a sport a bit later on. This fairly reflects the prominence of the "chess is a sport" argument.
You wouldn't go to the Shogi article and expect to read "Shogi is a Japanese sport" or even "Shogi is a Japanese mind sport" in the opening paragraph, but Shogi is highly organized and has serious competitions, just as chess does. MaxBrowne ( talk) 22:43, 3 November 2015 (UTC)
I'm a bit on the fence with this one. I removed the PROD to generate a discussion but I'm not really sure there's much to say about the topic. Maybe a description and illustration of chess fonts, like the old fashioned ornate font used by British publishers like Bell until the 60s, the Batsford-style font from the 60s-90s, and the modern fonts? Can't find much material on this topic on line either. MaxBrowne ( talk) 01:53, 1 December 2015 (UTC)
This is a new article created by User:Dino for the sequence 1.Nf3 d5 2.g3. The implication of the title is that there's a variation of the Réti Opening which is known as the King's Indian Attack. If one defines the Réti as simply the move 1.Nf3, then this is not unreasonable, but we still shouldn't have separate articles on the KIA and the "KIA variation of the Réti". It also remains common to reserve the term "Réti" for systems involving a quick c2-c4 hitting a pawn on d5, and the KIA for systems that do without this move (if an early central break is played it's usually e2-e4). Under this convention, the Réti and KIA are different openings – one is not a variation of the other. I thought this was already explained in our articles on the two terms as well as in Zukertort Opening. I suggest redirecting this article to King's Indian Attack. Cobblet ( talk) 09:44, 19 December 2015 (UTC)
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I too wondered of the similarity. But kept finding Internet references to the "Réti Opening, King's Indian Attack," plus a few books about it, as [1].
dino ( talk) 22:43, 19 December 2015 (UTC)
Yochanan Afek has apparently reported the death of Zvulon Gofshtein on Facebook. I'm looking for an official source for the information but can't find one. Maybe someone who can read Hebrew will have better luck? Cobblet ( talk) 03:35, 26 December 2015 (UTC)
זבולון גופשטיין שחמט
Could use a third party to weigh in at Talk:United States Chess Federation#"US Chess". I'm at 3RR. IP seems intent to edit war over the matter and hasn't yet used the talk page. It's possible I'm in the wrong here, but I don't think a common acronym should be dispatched with universally because an organization decides it's changing its marketing strategy. — Rhododendrites talk \\ 05:31, 10 January 2016 (UTC)
I've started a thread at Talk:Alexey Troitsky#Troitsky vs Troitzky in the article that project members may be interested in given the amount of attention that went into /Archive 31#Proposed changes to the Troitzky line article. -- Marc Kupper| talk 09:22, 4 February 2016 (UTC)
This article looks totally redundant to me. It started out as a redirect, then became a DAB page, then somehow it became an article. It has no coherent theme and there is nothing in the article that isn't covered better elsewhere in wikipedia. MaxBrowne ( talk) 23:25, 5 February 2016 (UTC)
Created articles for the next two women's editions 2016 (knock-out), 2017. I won't move the 2016 match article for now, guess it's fine now. Suggestions to improve? - Koppapa ( talk) 16:15, 14 February 2016 (UTC)
There is a widely debated topic on chess history, it is not clear whether it is based on facts or rumours/speculations. the topic is: "Alekhine-Capablanca world championship rematch." Some believe Alekhine avoided Capablanca and some believe contrary, ALekhine gave him a chance but Capa did not use it. can wikipedia enlighten all of us on this matter? p.s: I am not good at wikipedia, I cant add references and e.t.c. -- Sir artur ( talk) 19:53, 5 February 2016 (UTC)
Looking at the cleanup listings for the WikiProject and coming across the incomplete list section which as you would expect contains a lot of national championships. British Chess Championship is on the list but looking at the article I don't see any missing events. Given we can't add this years yet because it hasn't happened is there really a need for it to be tagged? Strictly speaking it should have a maintenance tag on there saying it is complete as of whenever, but then it'll appear in the "potentially dated" category. Jkmaskell ( talk) 18:00, 6 April 2016 (UTC)
This draft is at AFC for review, we need some advice about its notability and whether the sourcing is good. Please post your comments to the draft's talk page. Roger (Dodger67) ( talk) 15:42, 13 April 2016 (UTC)
A discussion started in template talk page, because I'm testing a new version in order to fix some displaying problems of current diagram. Please, join. -- Francois-Pier ( talk) 09:19, 15 April 2016 (UTC)
The recent edit and reversion at Two Knights Defense has got me thinking. The annotation symbols "!?" and "?!" are inherently subjective and reflect the opinion of the annotator; as such is it ever appropriate to use them in a wikipedia article? Maybe Harding says 4...Nxe4 is "?!", but other writers might give it a "!?". There's no particular reason to prefer Harding over Estrin or Beliavsky or the numerous others who have written about the opening. Maybe we should take the Hübner approach and award only question marks to objectively bad moves, leaving the "!"s and "!?"s and "?!"s to writers who are under no obligation to be neutral? MaxBrowne ( talk) 03:44, 12 April 2016 (UTC)
I added the 4...Nxe4?! material more than 3 yrs ago. Since it was difficult see who was quoting whom, I made some adjustments (added sources for Gligoric, Korn; everything not from Harding/Botterill is sourced individually now, perhaps that improves). Probably the 5.Nxf7? line can be eliminated as too detailed (overkill). ( Cobblet, maybe the entire 4...Nxe4 line is just a footnote/overkill, too!? If so feel free to delete.) Almost all the Harding/Botterill material after 5.Bxf7+ is also found in ECO C2 (1981, Gligoric), and that material has been carried over without change, to ECO C3 (1997, Matulovic). Of course anyone w/ more recent analysis should go ahead and improve the article. (Ya gotta start somewhere, right!? [Or the line can be deleted, as above.]) Cheers, IHTS ( talk) 07:36, 13 April 2016 (UTC)
Addendum: Oh! I see the point re "WP's voice", I think: 4...Nxe4?!, unattributed, was in the TOC (which might convey WP's voice). Instead of adding attribution to the TOC, I removed the symbol, so now only the article body has it. (If still unclear the symbol is attributed to Harding/Botterill, I can copyedit some more, just let know.) BTW, Gligoric also gives 4...Nxe4?!, and as mentioned Matulovic copies that, but Korn gives 4...Nxe4?) IHTS ( talk) 07:57, 13 April 2016 (UTC)
Anyway I've trimmed out the 8.d5 line per Maric's 9...Kg8! discovery. And I've re-placed couple supporting refs for better clarity. (My only src for 5.Nxf7? line is Harding/Botterill book. Everything after 7.Nc3! is contained in ECO C *2* and *3*, except the attribution of 7.Nc3! to Lopukhin, the attribution of 10.Bg8! to Estrin, and the subvar 8...e4 9.f3!, and those three things I'd found only in Harding/Botterill. [How much of that analysis is Lopukhin's I don't know; re attribution what I did was draw on Gligoric's assignment re C57 in ECO C *2*, p. 247.]) IHTS ( talk) 09:08, 14 April 2016 (UTC)