D91 Play from Grünfeld Defense: Three Knights Variation, Petrosian System ← Back to opening Play as: ♙︎ White ♟︎ Black New game Take back Flip board Resign Your move Type a move and press Enter: e4, Nf3, O-O, or from and to squares like g1f3 (e7e8q to promote). The board is also played with the mouse.