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

EGTB: draw

# move score
1 b4 draw
2 Ka7 draw
3 Kab7 draw
4 Kb6 draw
5 Kb8 draw
6 Kc7 draw
7 Kcb7 draw
8 Kd6 draw
9 Kd7 draw
10 Kc5 loss in 4 half-moves
11 Kd5 loss in 4 half-moves