It’s Your Move: daily chess puzzle # 209

White to play and win

Kavalek v Martinovic, Sarajevo 1968

Solution

I solved this prosaically, and, strangely, in the way my engine gives as best, but only in the sense that +4 is better than +3.8: 1 Rg4! breaks Black (1…g5 2 Bf4 ef 3 Qg2 and so on). But Kavalek found the far prettier:

1 Rg6!!

1…Ng6 (of course, I saw this far, but either didn’t see, or didn’t appreciate the strength of)

2 Bg5!!

and if 2…Qf7 then the f7 square is blocked, so 3 Qh2 and crashes through.