18-07-2013, 12:47 AM
Hi Clement. More interesting without the computers? Yes, might take a long time to get the right answer to the question, though. The human evaluation of the variation was a white win, and it was a computer suggestion we were analyzing! So no brownie points from Geoff anyway...
Just for the record, this is the famous game Alekhine-Capablanca 1927 I alluded to where White eventually won
[pos]8/5p1k/5rpp/8/P2R3P/6P1/5PK1/8 b - - 0 1[/pos]
Queens have just come off on d4 and the game continued 50 ... Kg7 51. a5 Ra6 52. Rd5 Rf6 53. Rd4 Ra6 54. Ra4. [Moves here <!-- m --><a class="postlink" href="http://www.chessgames.com/perl/chessgame?gid=1012518">http://www.chessgames.com/perl/chessgame?gid=1012518</a><!-- m -->]
Interestingly Capablanca chose not to play 50 ... Ra6 which would have prevented Alekhine from placing his rook behind the pawn. It would also have kept the passed pawn a square further back. Then Alekhine doesn't put his rook behind the pawn, but on the fifth rank, only getting behind the pawn when Capa invites him again. I'm not sure if this was standard knowledge, but 'rook behind the passed pawn' is supposed to be Tarrasch's rule. Tarrasch must have been furious! (Maybe Capablanca was against rules, as they stifle creativity :-) ). I don't know if this was right decision or not - most commentaries start after the moves Kg7 a5.
Quite interesting that textbooks use this example to illustrate 'the rules', without mentioning that both world champions flouted them!
[Interesting photo here <!-- m --><a class="postlink" href="http://www.chessgames.com/history/1007329-large.jpg">http://www.chessgames.com/history/1007329-large.jpg</a><!-- m -->]
And this is Botvinnik-Borisenko where Botvinnik had the pawn minus but drew despite the rook being in the wrong place - in front of the pawn
[pos]8/r7/5ppk/p6p/R7/6P1/5P1P/6K1 b - - 1 1[/pos]
1. ... Kg5? 2. f3 Kf5 3. g4+ hxg4 4. fxg4+ Ke5 5. h4 and Botvinnik obtained a passed pawn and soon drew.
Final moves here <!-- m --><a class="postlink" href="http://tablajedrez.blogspot.co.uk/">http://tablajedrez.blogspot.co.uk/</a><!-- m -->
Question: after g4+, might Black not still have won with Kg5 instead of Ke5?
[pos]8/r7/5pp1/p5k1/R5P1/8/7P/6K1 w - - 1 1[/pos]
The book says ... - but it's more interesting without the books
Just for the record, this is the famous game Alekhine-Capablanca 1927 I alluded to where White eventually won
[pos]8/5p1k/5rpp/8/P2R3P/6P1/5PK1/8 b - - 0 1[/pos]
Queens have just come off on d4 and the game continued 50 ... Kg7 51. a5 Ra6 52. Rd5 Rf6 53. Rd4 Ra6 54. Ra4. [Moves here <!-- m --><a class="postlink" href="http://www.chessgames.com/perl/chessgame?gid=1012518">http://www.chessgames.com/perl/chessgame?gid=1012518</a><!-- m -->]
Interestingly Capablanca chose not to play 50 ... Ra6 which would have prevented Alekhine from placing his rook behind the pawn. It would also have kept the passed pawn a square further back. Then Alekhine doesn't put his rook behind the pawn, but on the fifth rank, only getting behind the pawn when Capa invites him again. I'm not sure if this was standard knowledge, but 'rook behind the passed pawn' is supposed to be Tarrasch's rule. Tarrasch must have been furious! (Maybe Capablanca was against rules, as they stifle creativity :-) ). I don't know if this was right decision or not - most commentaries start after the moves Kg7 a5.
Quite interesting that textbooks use this example to illustrate 'the rules', without mentioning that both world champions flouted them!
[Interesting photo here <!-- m --><a class="postlink" href="http://www.chessgames.com/history/1007329-large.jpg">http://www.chessgames.com/history/1007329-large.jpg</a><!-- m -->]
And this is Botvinnik-Borisenko where Botvinnik had the pawn minus but drew despite the rook being in the wrong place - in front of the pawn
[pos]8/r7/5ppk/p6p/R7/6P1/5P1P/6K1 b - - 1 1[/pos]
1. ... Kg5? 2. f3 Kf5 3. g4+ hxg4 4. fxg4+ Ke5 5. h4 and Botvinnik obtained a passed pawn and soon drew.
Final moves here <!-- m --><a class="postlink" href="http://tablajedrez.blogspot.co.uk/">http://tablajedrez.blogspot.co.uk/</a><!-- m -->
Question: after g4+, might Black not still have won with Kg5 instead of Ke5?
[pos]8/r7/5pp1/p5k1/R5P1/8/7P/6K1 w - - 1 1[/pos]
The book says ... - but it's more interesting without the books