This week, we have an example of second-front strategy in the endgame. In the diagram position, the obvious move is 35.b4+, but after 35…axb4 36.axb4 Kd5 37.Bc4+ Kc6, followed by Nd6, it is not clear whether White can make any real progress.
Instead, Dydyshko focuses on the weakened light squares e4-f5-g6. which can provide a potential avenue for his king to raid the kingside, whilst Black is pre-occupied with stopping the passed b-pawn. 35.h4! prepares to fix those weaknesses with h4-h5. At move 36, Black responds to this possible kingside invastion by putting his knight on d6, to cover e4-f5, but then White turns his attention back to the queenside, by bringing his king to a4 to support the passed pawn. Black could have stopped this by playing 36…Nb6 instead, but then White would have shown his idea on the other flank: 37.Bc2 Nc8 38.g4! Nb6 39.Kd3! Kd5 40.Bb3+ Kc5 41.Ke4! and the king invades decisively on the king’s flank.
In the game, the invasion on the second front never actually happened, but the threat, as usual, proved stronger than its execution. Faced with threats on both wings, Black was unable to maintain the defence. His 39th was a blunder, which loses another pawn, but even after the superior 39…Kb6 40.b4 axb4 41.Kxb4!, White’s passed a-pawn will prove decisive.