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

EGTB: win in 4 half-moves

# move score
1 Kb4 win in 3 half-moves
2 Kb5 win in 3 half-moves
3 Kb6 win in 3 half-moves
4 Rb4 win in 3 half-moves
5 Rc4 win in 3 half-moves
6 Ka6 win in 5 half-moves
7 Kc4 win in 5 half-moves
8 Ra1 draw
9 Kc3 loss in 2 half-moves
10 Kc5 loss in 2 half-moves
11 Kd3 loss in 2 half-moves
12 Kd5 loss in 2 half-moves
13 Ke3 loss in 2 half-moves
14 Ke4 loss in 2 half-moves
15 Ke5 loss in 2 half-moves
16 Ra2 loss in 2 half-moves
17 Ra3 loss in 2 half-moves