Endgame: Marshall - Capablanca, match (game 5) 1909

Continuing with Capablanca's games 'to be studied', Capablanca wrote of the diagrammed position, 'It is from now on that it can be said that I played well. The ending is worth studying.' He gave no further notes.

The first question that comes to mind is, 'What is worth studying?'. Black is ahead in material a Bishop for a Pawn. Isn't this a simple problem of technique? Yes, it might be a technical win, but there is nothing simple about it. Black has three problems to tackle simultaneously:-

1. Stop the a-Pawn. It is not easily subject to capture, but stopping it from promoting isn't too difficult. The Queen and Bishop can form a battery on a diagonal to stop it from going to a6 or a8.
   
   
2. Stop the White Queen from harrassing the Black King, which has little Pawn cover. This job will go to the Black Queen, although the Black Bishop performs the important job of protecting Black's f-Pawn. The Black Queen can either block checks on the lines or prevent them by covering the checking squares.
   
   
3. Develop an attack against the White King. For this, the Black Bishop would appear to best placed on the a8-h1 diagonal.

It's also important to note that White can't allow a Queen exchange. If Queens are exchanged, the Black King moves to the Queen side and captures tha a-Pawn. The Black Bishop keeps the a-Pawn from promoting and prevents the White King from forcing the exchange of all Kingside Pawns. After eliminating all other Pawns, the h-Pawn promotion square is the right color for the Bishop.

Capablanca played 40...Bb1, protecting against 41.Qxd3. It is useless to attack immediately with 40...Qc1+ 41.Kh2 Qd2+ (41...Qc4 42.Qd7+ Kg6 43.Qe8+ Kf6 44.a4) 42.Kg1 Qe3+ 43.Kg2 Qe2+ 44.Kh3 Qf1+ 45.Kh2 Qf2+ 46.Kh1, when Black has gained nothing.

Match 1909
Capablanca, Jose Raul

Marshall, Frank
(After 40.Kh2-g1)
[FEN "8/7k/7p/3Q1p2/8/3b1PP1/Pq6/6K1 b - - 0 40"]

The game continued 41.a4 Qa1 42.Qb7+ Kg6 43.Qb6+ Kh5 44.Kh2 Ba2. The Bishop aims for d5. 45.Qb5 Kg6 46.a5 Qd4 47.Qc6+ Qf6 48.Qe8+ Qf7 49.Qa4 Qe6. Black can play 49...Bd5, but first positions the Queen for action against the White King. This prevents a continuation like 50.Kg2 Qe6 51.Kf2. Note how the Black Queen covers the White Queen's checking squares.

White played 50.a6. This lost immediately to 50...Qe2+ 51.Kh3 Bd5 52.a7 Bxf3 0-1, so it's a blunder. A better continuation would be 50.Qb5 Bd5 51.Kg2 Bc4 52.Qc5 (52.Qb2 Qe2+) 52...Qe2+ (With a battery on the a6-f1 diagonal.) 53.Kg1 Qe1+ 54.Kh2 Qd2+ 55.Kg1 Bd5 56.Qd6+ Kh5 (No more checks.) 57.Qe5 Qd1+ 58.Kh2 Qxf3 and wins anyway.

To play through the complete game see...

Frank James Marshall vs Jose Raul Capablanca, m 1909
http://www.chessgames.com/perl/chessgame?gid=1094814

...on Chessgames.com.