exchange of White's d-pawn for Black's c-pawn).

Themes for Black: Weakness of the d4-pawn, c6-c5 and e6-e5 breaks. The latter break is usually preferable, but harder for Black to achieve.

Slav formation

Openings: Primary: Queen's Gambit. Other: Catalan, Nimzo-Indian, Colle System, London System, and Trompowsky