[Khoth]

If you deliver checkmate, you lose. You have to instead force your opponent into a situation where they only have one legal move (which is trivially the best engine move).

[AstralStorm]

You can force the opponent into a position where the only move that saves them is a top engine move. Since they cannot play that move, the other option is to surrender.

So essentially this converts most mates in two into mates in one, but some become ties by repetition.

[throwawaymaths]

Not necessarily. There could be two ways to checkmate and you picked the one that was t the top move

[drdeca]

I don’t see how one way of checkmating could be worse than another way of checkmating? Do some engines give different scores for different check-mating moves? (Different moves from the same position I mean)