Fundamentals (part 22)

Spanton (156) - L Kuiken (152)
Hastings 3rd Week 1992

Black has just captured on a5 - what should the result be?

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31.a4! 1-0
The point is 31.a4 effectively gives the c pawn the power of being a protected passer, which means the white king is free to pick up the black pawns and then return to the queenside. However, there are pitfalls along the way, eg here is the ending played out against Stockfish10: 31...f5 32.Kd2 Ka6 33.Ke3 Kb7 34.Kd4 (not 34.Kf4? d4) Kc6 35.a5 g5 (35...Kb4 36.Kxd5 Kxa5 37.c6 etc) 36.a6 g4 37.hxg4 fxg4 38.a7 (but 38.g3? h5 is a draw) Kb7 39.Kxd5 Kxa7 40.Kd6 etc.