It’s Your Move: daily chess puzzle # 163

White to play and win

Larsen v Bednarski, Havana 1967

Solution

White has to act fast: if say 1 Re2, then 1…Bf6, and it is probably equal.

Part 1

So: (but read to the end)

1 Qe5! fe 2 Bc3

2…Bf8 3 Qh8+ Kf7[] 4 Qh7+ Ke6 5 Qg6+ Kd5:

This is as far as I could see from the initial position, and I wasn’t sure how about it- so much so, that as well as 6 de+ and 6 Re4, and some lesser moves like 6 b3, 6 Qg8+ or 6 Qh5+, I also looked at 6 c4+ Kd4 7 Bc3+, not realising that the B was on c3, so that 6 c4+ wasn’t possible. My intuition settled on 6 Re4.

Part 2

I tend to write my answers before checking them with engines, since my ultimate aim in doing my daily puzzles is to improve. Mostly, when I find errors or improvements, I amend what I have written. The above could be a textbook case of analytical errors.

6 Re4? is losing: Fritz gives it as -4; the amazing 6 Be5!! is White’s best, freeing White’s c2 pawn: 6…Re5 7 c4+ Kd4 8 Qf6!! is an impossible computer line, which is assessed as 0.0: 8…Qd2 9 Qf2+! e3[] 10 Qc2! e2! 11 Qc3+ Ke3[] 12 Qc1+ Kd3 13 Qc3+ Ke4 14 Qf3+! Kd4[] 15 Qc3+! is a perpetual;

But  5 Qg6+, which I thought was natural, is weaker than 5 Re4+! Kd6 (5…Kd5 6 Qd7+! is the point, and after 6…Rd7[] 7 Re8) 6 Qg6+ Kd5 apparently it is equal after the bizarre, to me, 7 b4- a move I would never think of, nor do I understand;

But 4 Qh7+ is also weak, and 4 Rf1+ is winning! 4…Ke6 5 Qe5mate, so 4…Qf5 is forced, losing the queen;

and 2…Bd6 is better than 2…Bf8, though White still wins by the idea of exchanging queens and picking up the Re8: 3 Qh8+ Kf7[] 4 Qh7+ Ke6[] 5 Re4+ Kd5[] 6 Qd7 and 7 Re8;

and 1…fe? is weaker than 1….Bh4 with advantage to Black: 2 Qe8+ Re8 3 Re8+ Kf7: Black is I think winning;

and 1 Qe5 is weaker than the move played in the game, 1 Bc3!, which is a better order of moves. Black can’t play 1…Bh4, and if he tries to prevent 2 Qe5 by 1…Bd6, White exchanges twice on e8, and then picks up the LPDO Bd6, and Black doesn’t have a mate or perpetual. So, 1 Bc3! fe 2 Qe5 and White wins as above (2…Bd6 3 Qh8+, 4 Qh7+ 5 Re4+ 6 Qd7 7 Re8). In the game, because Larsen found 1 Bc3, Black played 2…Bf8 and lost by the Qh7+/Rf1+ line.

but (1 Bc3!) Black has better: 1…c4!! which has the idea of interfering with White’s plans by the threat of Bc5+: If 2 Qe5 Bc5+ 3 Qc5[] fe 4 Qc4+ Qd5 and Black is better. White does though have 2 Re5!! and he is still winning, though to my eyes, the game still goes on 2…cd and only 3 cd! is winning, whereas the more natural 3 Qc4+ is only equal- all computer lines, of course;

but, rather than 1 Bc3!, which Larsen played, 1 Re6!! is best of all: it prevents 1…Bd6 (the Re1 is defended by the Bd2) and prepares to occupy the long black diagonal.

Part 3

This position shows how complex chess is, and how different engine chess is compared with human chess. I haven’t included diagrams in part 2, partly for length, but also because this puzzle would be a good one for home analysis and self-improvement. The lines I have given are only a selection.

But, in summary 1 Qe5? is weak because of 1…Bh4!; 1 Bc3 is good, but 1…c4 complicates it; and 1 Re6! is the best.

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