Talk:Pawnless chess endgame

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Absurdity[edit]

[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)

The one that moves first has the advantage. He can usually keep up an attack. Bubba73 (talk), 15:34, 30 June 2008 (UTC)
See the footnote I just added. Bubba73 (talk), 15:58, 30 June 2008 (UTC)
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)
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)

Botvinnik-Tal, 1961[edit]

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)

Summary Table[edit]

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 (talkcontribs)

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)

Rook versus rook?[edit]

Rook versus rook is not mentioned. Shouldn't it be? Magic9mushroom (talk) 14:27, 28 May 2012 (UTC)

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

Why two bishops vs. a lone king win only in 99,97 per cent cases?[edit]

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 (talkcontribs) 14:07, 14 October 2012 (UTC)

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)

Oh, forgive me for my commas. Of course, there should be dots in my question: 99.97 instead of 99,97. (I made this mistake because our country uses comma as decimal separator.) — Preceding unsigned comment added by Alex Chorny (talkcontribs) 19:58, 14 October 2012 (UTC)

a b c d e f g h
8
Chessboard480.svg
g8 black cross
f7 black cross
e6 black cross
d5 black cross
c4 black cross
b3 white bishop
c3 white king
d2 black circle
a1 white bishop
b1 black king
d1 black circle
8
7 7
6 6
5 5
4 4
3 3
2 2
1 1
a b c d e f g h
White to move, draw

Also a draw with the bishop on c4, d5, e6, f7, or g8 instead of b3. Also reflected with respect to the diagonal, and in the other corners. Bubba73 You talkin' to me? 22:07, 14 October 2012 (UTC)

In addition, the white king can be on d2 or d1. Bubba73 You talkin' to me? 22:17, 14 October 2012 (UTC)

Queen versus rook[edit]

The section queen versus rook is too short and doesn't present enough interesting features. — Preceding unsigned comment added by Nzarathoustra (talkcontribs) 11:38, 20 November 2012 (UTC)

Rook and Knight versus Bishop[edit]

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))

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)

7-men tables[edit]

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)

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)
Thank you, i will add more combinations. Sunny3113 (talk) 12:59, 28 March 2016 (UTC)
Yes, it is interesting. I haven't seen these seven-piece results before. Bubba73 You talkin' to me? 17:28, 28 March 2016 (UTC)

Are some of these reversed as to who wins? For instance Q+N versus three rooks. It seems like the winner should be the three rooks. There are some others too. Bubba73 You talkin' to me? 17:49, 28 March 2016 (UTC)

In many cases one of the defendant pieces get captured straight away in just few moves. For example here FEN: 5q2/R6n/8/8/6k1/8/3K3R/R7 b - - | ...Qd6+ and Qxh2 next with easy six-piece win. Sunny3113 (talk) 21:54, 28 March 2016 (UTC)

Three minor pieces versus two minor pieces?[edit]

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)

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)
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)