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 Kd5 win in 3 half-moves
5 Kd6 win in 3 half-moves
6 Kc6 win in 7 half-moves
7 Rb8 win in 7 half-moves
8 Ra8 win in 9 half-moves
9 Kc4 draw
10 Kd4 draw
11 Kc7 loss in 2 half-moves
12 Kd7 loss in 2 half-moves
13 Ke7 loss in 2 half-moves
14 Ke8 loss in 2 half-moves
15 Rc6 loss in 2 half-moves
16 Rc7 loss in 2 half-moves