Classical Variation, Classical Tarrasch Gambit

Instead of recapturing with 9...Bxc5, Black answers 9. dxc5 with 9...d4. This leaves White a pawn ahead, but the advanced pawn gains space and forces the c3-knight to move. The usual retreat is 10. Na4, and White has scored well with it. The main alternative is 10. Nb5, which attacks d4, and Black does better in practice against it. The engine gives White a slight edge, and the gambit is a rare sideline.