Simplicity in the Gunderam Defense to the BDG

Simplicity is the bane of the gambit player. The more Black can trade down pieces in the Blackmar-Diemer Gambit, the closer he comes to an endgame up a pawn. So it stands to reason that White usually prefers to keep the game complicated. I've lost too many BDGs to count where Black wins by that approach. So that would lead one not to play my sixth move in this game. But in this case it worked out.