Chess Engines and Game Analysis: Accuracy, Blunders and Stockfish
Engines are the strongest chess players on earth and the best training partners you have. Learn what their numbers mean, how accuracy and move labels are calculated, and how to use them to improve.
Chess Accuracy
How a single 0–100 score is built from your winning chances, move by move.
Open lesson ↗02Blunder vs Mistake vs Inaccuracy
Three sizes of error, measured in lost winning chances, with real examples of each.
Open lesson ↗03How Strong Is Stockfish? Engine vs Magnus Carlsen
Stockfish rates near 3,800 against engines; the best human is 2823. The gap is huge, and here is the math.
Open lesson ↗04Stockfish Levels Elo Chart
We ran Lichess's exact level settings through 720 rated puzzles. Here is what each Stockfish level really plays at, and which one to pick.
Open lesson ↗05Stockfish vs Leela
Two ways to build a top engine, who wins today, and which one to use for analysis.
Open lesson ↗06Stockfish NNUE and Versions
What NNUE is, how Stockfish has changed since 2020, and which engine you are actually running.
Open lesson ↗How to use an engine to improve
- Play your game first; analyse it only afterwards.
- Find the two or three moves where your evaluation dropped most, not every small inaccuracy.
- Ask why the engine’s move is better before accepting it; test your idea on the analysis board.
- Turn those positions into exercises in Practice my mistakes and repeat them a day later.