Nice, it works :-) I was about to complain it's too easy on the highest level..then realized I had it set to only 2 ply ahead! Did you try RealChess? Created by Shiela Timp, Jorden van Foreest's mother. It's where I'd seen the "set number of blind moves" feature before. They're not just "there's a winning tactic here" positions, but finding the best move.