Krejcik Variation

The Krejcik Variation, 2. Bc4, ignores the attack on e4 and simply develops, leaving the pawn en prise. It is named after the Austrian master Josef Krejcik, who introduced it in 1922. More than half of Black's replies are 2...Nxe4, and White's follow-up is then the Krejcik Gambit, 3. Bxf7+ Kxf7 4. Qh5+ Kg8 5. Qd5+ e6 6. Qxe4. White gives up the bishop to win back the knight and restore material equality, whereas the check on the other side, 4. Qf3+, fails to 4...Nf6. The cost is considerable. White has given up a developed piece and the central pawn, while Black keeps the bishop pair, a sheltered king and unobstructed development. After 6...d5 7. Qe2 e5 8. Qxe5 Nc6 Black returns a pawn to gain a large lead in development. The alternative 4...g6 5. Qd5+ e6 6. Qxe4 Bg7 7. Qf4+ Ke8 is also regarded as comfortable for Black.

Black can sidestep the tactics with 2...e6 or 2...d5, while 2...e5 transposes to the Berlin Defense of the Bishop's Opening. Engines give Black a slight edge, Black also scores better in online games, and the line is rarely seen in serious play.