[plank]

Winning is not possible: only the queen is strong enough to win against two bishops, and that fails to the check and loss of queen from black tiled bishop.

So draw is most one can get. Underpromoting to knight (with check, thus avoiding the check by the bishop) is the only way to promote and keep the piece another move.

I guess in this situation the knight against two bishops keeps the draw.

[dmurray]

> I guess in this situation the knight against two bishops keeps the draw.

Yes, though - I think I can say without exaggeration - no human on earth can tell you exactly which positions the knight can hold out against the bishops for the required 50 moves.

So it's a strange problem: a perceptive beginner can find the right move through a process of elimination, but even a super-GM can't be certain it's good enough, or defend it accurately against a computer. I don't see anything about that that makes it a particularly good test of an LLM.

[echoangle]

I didn’t even know you could pick which piece you want to promote to. But I’m also not an average chess player.

So the correct move is to move the Pawn up and promote to knight?

Thanks!