Talk:Pawnless chess endgame

message: [Queen and a rook versus a queen and a rook]: "Despite the equality of material, the player to move wins in 67.74 percent of positions".  This cannot be - the 2:1 advantage cannot switch from one side to the other at each move.  AMackenzie (talk) 11:13, 30 June 2008 (UTC)
replies: text: The one that moves first has the advantage.  He can usually keep up an attack.  Bubba73 (talk), 15:34, 30 June 2008 (UTC)

text: See the footnote I just added.  Bubba73 (talk), 15:58, 30 June 2008 (UTC)
replies: text:  It is, in fact, not absurd at all. Let's say White is to move; in a randomly generated position there is a 2/3 chance White can win. After White's move, the position is not randomly generated and so the previous statement does not imply there is a 2/3 chance Black can win. White aims to leave, after each move, a position belonging to the minority that is still winning for White. Since the queen and rook have great mobility on an open board, chances are in his favour that he will be able to do this. 91.105.33.98 (talk) 15:35, 19 December 2010 (UTC)
replies: text:  That is a good explanation, thanks. (And if White was not winning, he certainly would want to avoid moving into a position where he would be losing.) Bubba73 You talkin' to me? 15:42, 19 December 2010 (UTC)
thread_title: Absurdity

message: Tal talked about this position in his book The Life and Games of Mikhail Tal, but I can't find it again.  The score of the game was not given, nor the position. But he talked about going into it because he had encountered this before (on the short end, I believe).  If what he says about it can be located, it might make a good addition to the article.  Bubba73 (talk), 02:46, 2 July 2008 (UTC)
thread_title:  Botvinnik-Tal, 1961 

message: According to the summary table, every pawnless endgame listed except one is described as "easy" despite the fact that some are described as being difficult or tricky in this article's notes (19,20).  Furthermore, the Wikipedia article on the Cochrane Defense describes it as difficult, and it is easy according to the table.  Also, many of the endgames listed on the table do not have notes referenced. — Preceding unsigned comment added by 74.243.102.152 (talk • contribs) 
: You are right.  All of those assessments in the table come from one source.  There are some footnotes from more expert players (e.g. Nunn) that say differently.  It may be best to take those assessments out.  Bubba73 You talkin' to me? 16:06, 1 February 2012 (UTC)
thread_title:  Summary Table 

message: Rook versus rook is not mentioned. Shouldn't it be? Magic9mushroom (talk) 14:27, 28 May 2012 (UTC)
replies: text: It isn't in any of my three main references: Secrets of Pawnless Endings, Fundamental Chess Endings, and A Pocket Guide to Chess Endings.  But it will be a draw except when there is a quick checkmate or win of the other rook.  Bubba73 You talkin' to me? 17:12, 28 May 2012 (UTC)
replies: text:  I figured as much, but it should still be mentioned given that two knights vs. king is. Magic9mushroom (talk) 17:21, 28 May 2012 (UTC)
replies: text:  There is a lot more to say about Two knights endgame, and it is referenced.  So far I haven't found a reference for rook versus rook. It is sort of surprising that it isn't in those references but queen versus queen is, but Q vs Q does have deeper and more subtle lines. Bubba73 You talkin' to me? 19:09, 28 May 2012 (UTC)

text:  OK, I found a reference and added it under "major pieces only".  Bubba73 You talkin' to me? 20:02, 28 May 2012 (UTC)
thread_title:  Rook versus rook? 

message: I have already understood that bishop + knight win in 99,5% (not 100) because the defending king can give a fork on them if they are poorly placed at the beginning of the endgame.
But what about two bishops endgame? Can someone explain why 99,97% but not 100?  — Preceding unsigned comment added by Alex Chorny (talk • contribs) 14:07, 14 October 2012 (UTC)
replies: text: That's a good question.  If White is to move, the two bishops are on opposite color, and it is a legal position, it can't be a fork. I can't think of a position that is not a win for the bishops.  I'll ask around.  Bubba73 You talkin' to me? 15:37, 14 October 2012 (UTC)

text: In addition, the white king can be on d2 or d1.  Bubba73 You talkin' to me? 22:17, 14 October 2012 (UTC)
thread_title:  Why two bishops vs. a lone king win only in 99,97 per cent cases? 

message: The section queen versus rook is too short and doesn't present enough interesting features.  — Preceding unsigned comment added by Nzarathoustra (talk • contribs) 11:38, 20 November 2012 (UTC)
replies: text: I don't think it is too short, but rather quite long with many examples that are quite confusing for the novice, who might want to find a simple description of the "winning process" instead of lots of "random information" which is of not much use without knowing what would be the correct play. — MFH:Talk 02:27, 5 February 2022 (UTC)
thread_title:  Queen versus rook 

message: Is missing - FWIW, intuitively, I would say this is a win for Rook + Knight, but I couldn't find a definitive answer anywhere
(178.12.33.158 (talk) 14:37, 2 October 2016 (UTC)
replies: text: I'm pretty sure that it isn't in the references that were used.  However, the rook and knight should be able to at least force the exchange of the minor pieces and then win.  Bubba73 You talkin' to me? 15:07, 2 October 2016 (UTC)
thread_title:  Rook and Knight versus Bishop 

message: This table shows seven-piece endgames. 
I have 1-year subscription of Lomonosov Tablebases and i can add the remaining info. Sunny3113 (talk) 18:37, 27 March 2016 (UTC)
replies: text: I like what you did.  ClueBot reverted it, but I reported that as a false positive.  Bubba73 You talkin' to me? 22:22, 27 March 2016 (UTC)
replies: text:  Thank you, i will add more combinations. Sunny3113 (talk) 12:59, 28 March 2016 (UTC)
replies: text:  Yes, it is interesting.  I haven't seen these seven-piece results before.  Bubba73 You talkin' to me? 17:28, 28 March 2016 (UTC)

text: I understand this would probably take more work, but surely it should be possible to exclude such cases by cutting out those with very early conversions? Positions where conversion happens quickly due to a piece being tactically lost are surely not relevant to the average evaluation of the 7-man endgame in question. Double sharp (talk) 14:31, 13 April 2019 (UTC)
thread_title:  7-men tables 

message: This is not included in the list. I imagine it should be a draw in most cases, but with 3 minor pieces versus 1 included it seems to be a natural follow-up question. Double sharp (talk) 15:36, 16 September 2017 (UTC)
replies: text: It wasn't in any of the sources I used, but I'm pretty sure that generally it would be a draw.  If a pair of the poeces is exchanged, it is down to 2 minor pieces versus 1, which is normally a draw except for two bishops vs one knight.  Bubba73 You talkin' to me? 16:51, 16 September 2017 (UTC)
replies: text: I haven't found any good sources for this either. OTOH, after a few searches I found that Marc Bourzutschky (one of the "wizards of 7-men endgames", as Tim Krabbé puts it) once addressed this in a post on the Rybka Forum, in which he claimed that the only generally winning cases of this endgame are BBN vs NN and BBN vs BN (assuming the bishops are on opposite colours). I am not sure if this is reliable enough, though, despite the authority of the poster; it may yet fall under the third exception under WP:USERGENERATED. What do you think? Double sharp (talk) 13:06, 17 September 2017 (UTC)
replies: text: Well, I have added it with this source, even if not ideal, because of the authority of the poster and the interestingness of the result. Double sharp (talk) 01:13, 25 February 2019 (UTC)
replies: text:  Thank you for adding that - I think it is good.  Bubba73 You talkin' to me? 01:44, 25 February 2019 (UTC)
thread_title:  Three minor pieces versus two minor pieces? 

message: I removed this due to lack of sourcing, but Paul Lamford has confirmed that the incident did indeed happen. Possible sources include Tim Krabbe's Chess Curiosities and Europe Echecs. MaxBrowne2 (talk) 03:06, 3 February 2019 (UTC)
replies: text: I didn't find it at Krabbe's site.  And it isn't in chessgames.com. Bubba73 You talkin' to me? 03:41, 3 February 2019 (UTC)
replies: text: This was the event, but the game does not appear in the databases. MaxBrowne2 (talk) 04:06, 3 February 2019 (UTC)
replies: text:  I know that we are supposed to use secondary sources, not primary sources.  But in this case, I'll accept a primary source, i.e. a personal communication from Lamford.  It would be nice if he has a scoresheet or PGN file.  Bubba73 You talkin' to me? 05:15, 3 February 2019 (UTC)
replies: text:  No we can't do that. It needs to be published somewhere. MaxBrowne2 (talk) 05:31, 3 February 2019 (UTC)
replies: text:  The editor that made that edit is anonymous, so they knew about it somehow, but they probably aren't around to ask.  Bubba73 You talkin' to me? 06:18, 3 February 2019 (UTC)
thread_title:  The 3 rooks vs 2 rooks incident 

message: I realise that we are unlikely to have any information about 8-man endgames like this one, but since Q ~ 2R and Q vs 4 minors is included, it seems a natural enough question. (I would guess that it is generally a draw if they are the normal four minor pieces as the stronger side can sacrifice his rooks for the opponent's bishops.) Double sharp (talk) 02:05, 27 February 2019 (UTC)
replies: text: I think that is probably true.  The two rooks have more defenses against four minor pieces than a queen does.  Bubba73 You talkin' to me? 02:21, 27 February 2019 (UTC)
thread_title:  Two rooks versus four minor pieces? 

message: *3 minors vs 2 minors, in normal situations, is a win exactly when the stronger side has the bishop pair and the weaker side lacks it.
*If there are same-coloured bishop pairs, weird things can happen. BBN (different colours) vs BB (same colours) is not generally won, but has very long winning lines (220 moves to capture).
*R + 2 minor vs R + 1 minor is general win, agreeing with what Speelman reported as the thought of 1981. Apparently this was surprising when found out, though.
*2R + minor vs 2R is not generally won, but is won more often than was thought.
*When queens are around, tempo is more important than material. QQ vs QQN is won for the weaker side half the time, when he has the move!!
Double sharp (talk) 07:40, 3 March 2021 (UTC)
replies: text: Nice. Can you incorporate these into the article?  Bubba73 You talkin' to me? 07:44, 5 March 2021 (UTC)
replies: text:   Double sharp (talk) 07:48, 6 March 2021 (UTC)
thread_title:  Surprises from the aforementioned [http://rybkaforum.net/cgi-bin/rybkaforum/topic_show.pl?tid=25373 post by Marc Bourzutschky]