Play chess against a 400-rated computer

A 400-rated player moves fast and looks one move ahead at most. Expect pieces left hanging, early queen raids and missed checkmates. It will also take anything you leave unprotected.

119

average loss per move (centipawns)

9.2

big blunders per 100 moves

3.1s

average think, 10-minute game

1

moves it looks ahead

For comparison, real Chess.com rapid players around 400 lose about 101 centipawns per move (measured on their own games, the same way). The bot is Rookie Theo (400): see how the bots are built.

You know how the pieces move and want a first opponent that won't crush you.

1. 1Before every move, ask: what can it capture? Then protect it.
2. 2Take free pieces: at this level they appear every few moves.
3. 3Learn one checkmate pattern (back rank or queen + king) and use it.

Measured on 41 Chess.com players' public games, November 2026.

We picked random public Chess.com players rated 400 to 2000 and took their 5 most recent rapid games. Stockfish scored every move they played from move 5 on, comparing it with the best move, and we averaged the loss per move. We fitted a smooth trend through all the players so no single game sways a rating, then ran our bots through exactly the same measurement.

Correction: our first version used textbook reference values that overstated human mistakes; the bots are now tuned to these measured numbers.