Click on the third or sixth rank to set the en passant target square.

EGTB: win in 1 half-moves

# move score
1 Rxf4 win in 47 half-moves
2 K4xf4 loss in 2 half-moves
3 K5xf4 loss in 2 half-moves
4 Rxb6 loss in 1 half-moves