Fundamentals (part 50)

Spanton (1888) - Mustafa Atakay (1874)
Gibraltar U1900 2018

White to play and draw

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31.f4?
This loses in two possible ways, so White has to try 31.e4, when play gets tricky. The analysis engines Komodo11.01 and Stockfish11 give best play as 31...g4! (only move not to lose - I will show why later) 32.fxg4 fxe4 33.g5 e3 34.g6 e2 35.g7 e1=Q 36.g8=Q+ with a draw. The engines show 31...fxe4 loses to a beautiful zwischenzug: 32.fxe4 g4 33.e5 h4 34.b6!! (only drawing is 34.e6 g3 35.hxg3 hxg3 36.e7 g2 37.e8=Q g1=Q when the queens have multiple checks as in the previous line) axb6 35.e6 g3 36.hxg3 hxg3 (36...h3 also loses, albeit more slowly) 37.e7 g2 38.e8=Q g1=Q 39.Qb5+ (allowing this check was the point of 34.b6!!) Kd4 40.Qxb6+ etc.
The game finished:
31...g4
31...gxf4 32exf4 Kb4 also wins.
32.e4 h4 33.exf5 g3 0-1