The Dutch Defense is one of Black's most combative responses to 1.
d4, and the Stonewall is the boldest version of this opening.
Black immediately seizes space in the center and clamps down on the e4-square, laying the foundations for a complicated strategic battle.
Many players believe the Stonewall to be a substandard opening, naively assuming that the e5-outpost and bad light-squared bishop must give White the advantage.
GM Nikola Sedlak disagrees, and in Playing the Stonewall.