Kasparov, commenting on Euwe's game against Speyer in the 1924 Dutch Championship, wrote, “This is ... a classic ambush with the threat of discovered check.”
The concept of an ambush hadn't occurred to me before but I didn't need to read it twice to realise that this is a device we've all employed at one time or another (“I'll play this—and then, if he doesn't realise what I have in mind, I'll get him here.”) It's fun when it works out but down here in Patzerland, many of those ambushes are flawed and, by attempting a flamboyant trap, I've sometimes lost games that I might have won by giving my opponent credit for having two eyes and a brain.
Nevertheless, I was enchanted by the idea of ambushes and went looking for them in master games. The annotations in the Euwe-Speyer game are Kasparov's but I'm to blame if there's any faulty analysis in the others. If anybody wants to comment, please feel free to wade in.
In the next game Capablanca's c-pawn was getting a little above its station, and Ossip Bernstein didn't need Nimzowitsch to point out the danger. Surprisingly, Capa made it fairly easy for him to win it, moving his rook forward and back where the White's knight could attack it while manoeuvring toward the pawn. Inevitably the pawn fell and if Berstein was relieved to capture it so easily that relief didn't last long. When Capa sprung his ambush with a queen sacrifice on move 29, Bernstein resigned. Object lesson for young players—when you calculate a combination be certain you know what the board will look like when it's completed.
In 1857 France and the United Kingdom declared war on China, an earthquake in Tokyo killed more than 100,000 people, and the “Panic of 1857” set off one of the most severe economic crises in U.S. History. And over the chessboard there was another panic—this time on the part of Napoleon Marache when he realised that Paul Morphy had just ambushed him. Played with typical Morphy magic, this game barely lasted twenty moves.
Sometimes even the best don't see it coming. At his peak Ulf Andersson reached #4 in FIDE's world rankings and this game was played the year he earned his GM title. Bill Hartston, with the black pieces, perhaps had a home ground advantage, for the game was played at Hastings in 1972. There had been a great deal of manoeuvring during the game and the diagrammed position is after Hartston had just played 35...Nf6, a seemingly innocuous move, but one which was critical to the sacrifice that followed, for cooperating with the g5 pawn it formed an invisible, but impenetrable ambush across f4, g4, h4. Andersson pinched the c7 pawn and the queen, hussy that she was, snuggled up to the white king and said, “Your place or mine?” Andersson resigned rather than face 37.Kxh3 Bf1#.