Test your chess: Reitstein problem 202

White to play and win

Reitstein's rubric for this puzzle, given since I found it really tough is: Spencer assessed this position well: with his next move he converted a superior game into a winning advantage. What did he play?

RT Spencer v D Macfarlane 1978

Solution

Because of the clue, I knew that time was of the essence, and sensed that 1 Bc5! was the move, which in fact it is.

However, I couldn't easily visualise the position after 1…Qc5 (1…dc 2 Ree7 is even better for white than after 1…Qc5) 2 Ree7 Bd4.

Alas, I failed to see my way through the complexities of this position.

Which is better? 3 Rac7; 3 Rf7+; or 3 f5?

Solution

Reitstein gives 3 Rac7 'and wins', and indeed it does, after 3…Bg1+ 4 Kh1 Be3 5 Rf7+; or 3…Qd5 4 Rf7+ Kg8 (4…Qf7 5 Rf7+ Kf7 and the LPDO Bd4 drops off, 6 Qd4 1-0);

3 f5? loses to 3…Kg8! and black can defend, with for instance one point being that after Qc5-d5, there is the threat of Bg1+ winning the LPDO Qd2;

3 Rf7+! is the most accurate, when 3…Kg8[] 4 Qe1! or 4 Qe2! wins.

If I were marking myself, I would give myself 7/10: and in an actual game, I could easily have messed up, by for instance checking or not checking on f7, or playing f5, or making the wrong choice between Qe1 and Qe2: the precise move depends on the particular line chosen.

When I entered the position into Stockfish it at first said that 1 f5! was strongest, giving it as winning set +2; but after a while, it changes its preference to 1 Bc5, at +5. My above analysis is not as thorough as normal: there are many variations (a thicket, in Kotovian terms) and this would be a good position my readers to self study or play against an engine.

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