Tsume Othello #5622100 (empty 10)
To move: Black — find the best move
a
b
c
d
e
f
g
h
1
2
3
4
5
6
7
8
28 26
Why this move works
The answer is h5. Even best play finishes 6 behind, but h5 keeps the most discs for you (2 better than the next-best).
f7 flips 3 right now, yet it is not best. Reading to the end to keep every possible disc is the essence of endgame othello.