I wrote about the diagram: “This type of positions is considered to be a theoretical draw because the Black rook is behind the ‘a’ pawn.” Well, I forgot about the entire chapter on this type of positions that I had read in Mark Dvoretsky’s “Endgame Manual” . Apparently in 2003 a few very important ideas were found for White, that give him many additional winning chances. Wikipedia describes the plan as follows:
Recent theoretical analysis of this position shows that White has a strong manoeuvre:
- advance the pawn to the sixth rank
- move the king towards the queenside
- when the black rook takes a kingside pawn, switch the rook to guarding the pawn from the c-file, i.e. Rc7 then advance the pawn to a7.
- Switch the white rook to the a-file with gain of tempo. Thus Black is forced to sacrifice his rook for the pawn without White having to move his king all the way to a7. These many extra tempos make the difference between winning and drawing or even losing.
The point of White’s play is that when the Black king advances – White threatens to give a check and block the ‘a’ file with the rook:
Black to move. White threatens with Rc5+, followed by Rc4-a4, or Rc6-a6, all with tempo.
In Bacrot – Robson, White had a good chance to play for a win in this position:
White to move.
Bacrot played 60. Ra8?, but better was 60. Kd4!, giving up the pawn with the rook on a7 (where it attacks the pawn on f7).
The position in Wikipedia article is the exact one as in Bacrot – Robson, and it is given as winning! So Bacrot missed his win first, before Robson blundered in the clearly drawn position in the very end. It appears from the way Bacrot played this endgame, he had not known or remembered about this endgame research by Dvoretsky!