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

EGTB: win in 4 half-moves

# move score
1 Rb8 win in 3 half-moves
2 Ka3 draw
3 Ka5 draw
4 Kb3 draw
5 Kb4 draw
6 Kb5 draw
7 Ra8 draw
8 Rc8 draw
9 Rd8 draw
10 Re1 draw
11 Re2 draw
12 Re3 loss in 2 half-moves
13 Re4 loss in 2 half-moves
14 Re5 loss in 2 half-moves
15 Re6 loss in 2 half-moves
16 Re7 loss in 2 half-moves
17 Rf8 loss in 2 half-moves
18 Rg8 loss in 2 half-moves
19 Rh8 loss in 2 half-moves