Chess Coach

Use when you want to know where a game turned and what you could have played instead, with every judgement coming from a real engine rather than a guess. A script scores each move against Stockfish's own choice from the same position, classes the difference in centipawns, and builds a board you can step through with the better move drawn as an arrow; the explanation sticks to the engine's lines and the material count.

Do not use it without Stockfish installed (it then only replays the game and analyses nothing), for chess variants, or as a promise of rating gains.

Requires: Python 3.9+ with the python-chess package (pip install chess) and the Stockfish engine installed on the same computer (for example brew install stockfish, sudo apt install stockfish, or a download from stockfishchess.org). The board is a single HTML file that opens in any browser. No internet access needed.

Want to play instead of review? Try the free Chess vs Claude skill.