Chess vs Computer

How the chess bots work

Bots from 1320 Elo up use Stockfish's calibrated strength limiter. Lower levels pick from the engine's candidate moves with a deliberate margin for error, so they make the kind of mistakes real beginners make. Every game ends with a free Game Review: accuracy for both sides, each move classified from Brilliant to Blunder, the best alternative, and an evaluation graph of the whole game.

Game Review move classifications

• Brilliant (!!): a good piece sacrifice.
• Great (!): the only move that keeps the position.
• Best / Excellent / Good: how close your move was to the engine's top choice.
• Inaccuracy (?!), Mistake (?), Blunder (??): how much winning chance a move gave away.
• Miss: your opponent made an error and you didn't punish it.