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

EGTB: win in 4 half-moves

# move score
1 Kb7 win in 3 half-moves
2 Rb7 win in 3 half-moves
3 Ra5 win in 7 half-moves
4 Ra1 draw
5 Ra2 draw
6 Ra3 draw
7 Ra4 draw
8 Kb6 loss in 2 half-moves
9 Kb8 loss in 2 half-moves
10 Kc6 loss in 2 half-moves
11 Kc8 loss in 2 half-moves
12 Kd6 loss in 2 half-moves
13 Kd7 loss in 2 half-moves
14 Kd8 loss in 2 half-moves
15 Ra6 loss in 2 half-moves
16 Ra8 loss in 2 half-moves