The rarely-sprung trap

1.e4 Nf6 2.e5 Nd5 3.d4 e6?! 4.c4 Bb4+?? is an ingenious but bad way of playing Alekhine's Defense. It is seen 19 times in Mega Database 2013. Some good players had White, including the Filipino GM and former Candidate Eugenio Torre, and two other players rated over 2300. In 16 of those games, White played 5.Bd2; in the other three, he played 5.Nd2. In none of the games did White play 5.Ke2!, winning a piece, since after either 5...Nb6 6.c5 or 5...Ne7 6.a3, Black's bishop is trapped and will be lost. White, modestly rated 1197, did find the sockdolager (as the old-time writers liked to say) in the below correspondence game, presumably aided by the greater time available for reflection.

This game is from Karsten Müller and Rainer Knaak's book 222 Opening Traps After 1.e4, p. 18. I first learned of this trap in Tim Krabbé's wonderful Open Chess Diary (scroll down to No. 381). As I have previously noted, I have myself won with the mirror image of this trap, 1.d4 Nc6 2.d5 Ne5 3.e4 d6 4.f4 Bg4?? 5.Qd2! and Black loses a piece just as in the original version.