Classical Variation, Central Variation

The Central Variation meets the Classical bishop on c5 with 4. c3, preparing d4 to build a broad pawn center and drive the bishop back. The move also creates a concrete threat. With d4 no longer available to Black's queen, the e5 pawn can fall to Bxc6 and Nxe5. After 4...a6? 5. Bxc6 dxc6 6. Nxe5, Black lacks the ...Qd4 resource. The best try, 6...Qe7 7. d4 Bd6 8. O-O, regains the pawn but leaves White with a slight edge in development.

4...Nf6 is the standard reply and the engine's choice. It can be met by 5. d4, hitting the bishop, or by 5. O-O, which transposes to the Zukertort Gambit of the Berlin move order. In online games, 4...d6 is played even more often, but it is an error. It blocks the bishop's retreat, and 5. d4 exploits this: 5...exd4 6. cxd4 Bb4+ 7. Kf1 Bd7 8. Qa4 a5 9. a3 traps the bishop, while 5...Bb6 6. d5 wins the knight. Rarer options include the Charousek Variation 4...Bb6 and two gambits, the Cordel Gambit 4...f5 and the Konikowski Gambit 4...d5. White holds a slight edge, and draws are rare.