Comment by billforsternz

I am skeptical about the idea of starting with king, bishop and knight versus king. Winning this endgame from an arbitrary start position requires something like 25 moves / 50 ply. Brute force minimax plus alpha beta will struggle to do that in a reasonable amount of time without sophisticated pruning. And you can't progress gently to the goal starting with simple 2 or 3 ply calculations because mate is the only point of the calculation here, normal material and positional factors are irrelevant. It makes more sense to first make sure your engine can win material with a simple knight fork say, and build from there to multi move material winning combinations. Followed by pursuit of positional goals when material gain is impossible (control the centre, seek scope for the pieces etc.). The elementary mates are actually a problem area for engines because they require a rather atypical strategical approach, cutting off the king, bringing your king around, shrinking the box, eventually forcing mate.