The Stonewall Defense is an extremely effective chess opening for black against 1. d4 – representing a solid system that is very difficult for white to crack. The Stonewall Defense involves black placing pawns on the light squares d5, e6, and f5 to establish an iron grip on the center, specifically restricting a potential breakthrough by white involving an e4 push. Even if you aren’t crazy about playing the Stonewall Defense against every set-up by white in the Queen Pawn opening systems, the Stonewall Defense is exceptionally versatile and very easy to transpose to from various chess openings for black against 1. d4, 1. c4, 1. Nf3, etc.