Lessons From Bad Herrenalb VIII

IN round eight I reached the following position as White.

Black has just played 18...g5?! 

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I replied 19.Bg3?!, which gives a pleasant advantage, but the game was drawn on move 36.

I wanted to capture on g5, but after Black recaptures and White continues 20.Qh5 there are quite a few continuations to consider, all of which must work for White if the capture on g5 is to prove correct.

Easily dismissed is 20...Bxd2? as that unprotects the f6 square, so White has 21.Qxf7+ Kh8 22.Qf6#.

Stockfish16.1 reckons best is 20...Rxd2, but calculates that 21.Qxg5+ and 22.Rxd2 leaves White the equivalent of more than a minor piece ahead.

Dragon1 fluctuates between Stockfish16.1's choice and 20...Bg6, but reckons that after the latter White is the equivalent of almost a rook ahead on playing 21.Qxg5.

The move that stopped me playing 20.Bxg5! was 20...h6. On 21.Qxf7+ Kh8 I missed that 22.Rxd8+ wins. The point is 22...Bxd8 allows 23.Qg8#, so Black has to give up the queen with 22...Qxd8, but 23.Rxd8+ Rxd8 24.Qxf5 is overwhelming.

LESSON: when most lines of a winning combination work, but one line seems not to, it is worth spending a lot of time ensuring there is not after all a way to make the combination sound.