Last time we left off with this critical position, from a variation of the game between Matti Rantanen and James Walsh, in the 1956 Moscow Olympiad.
Solution
Although this position wasn’t actually reached in the game – Black deviated earlier and lost differently – it’s really the key to the whole line. The only winning line starts with 60.Nf6+! Kc4
Now White shows the point of the last move with 61.Ng4!
The knight stops the bishop from sacrificing itself for the pawn! If White had carelessly pushed the pawn, Black would have captured it with the bishop. After capturing the White b and a-pawns, his queenside counterplay would have allowed him to draw. The White h-pawn is far too important to be ‘traded’ for a mere bishop.
Play continued 61…Kxb4 62.h5 Bc2 bringing up another nice moment.
Now 63.Ne5! is not the only win, but it is very convincing. White threatens Ng6, cutting off the bishop’s control of h7. So Black plays 63…Bh7, trying to block the pawn.
Both sides then follow their plans: White wants to promote the h-pawn, while Black seeks queenside counterplay. 64.h6 Kxa5 65.Kf6 Kb4 66.Kg7 Bc2 brings up the last important moment.
67.Ng6! cuts off the bishop’s control of h7 once and for all. This final diagram shows that White’s far advanced passed pawn carries the day, rendering Black’s temporary material advantage irrelevant. 67…a5 68.h7 promotes the pawn and wins.
Key Ideas
1) The idea of 60.Nf6+!, followed by 61.Ng4!, blocked the bishop’s control of h5. This paved the way for the pawn to advance, without allowing the bishop to sacrifice itself for the pawn.
2) White could afford to allow the Black king to infiltrate the queenside, since Black was never in a position to stop White’s quick passed pawn. In the final position White’s passed pawn approaches touchdown while Black’s pawn is nowhere near.