Why doesn't Lichess analysis explain itself?

• Lichess computer analysis is Stockfish evaluating each position; it reports numbers and lines, not reasons.
• Lichess converts Stockfish's centipawn score into Win% and marks inaccuracies, mistakes and blunders by how much your Win% dropped.
• Lichess says accuracy is not a test grade: complex positions lower it and lopsided positions can inflate it.
• Learn from your mistakes, available after a computer analysis, asks you to find a better move before it shows one.
• Different sites use different formulas, engines and depths, so Lichess and Chess.com accuracy for the same game can differ.

It shows how your winning chances changed after each move, according to Stockfish. Everything on the analysis page is derived from that one number per position.

Source: Lichess Accuracy page, read on 28 October 2026. Lichess says Win% is also the metric behind its evaluation bars and evaluation graphs.

An engine compares outcomes, not ideas. Lichess's own explanation is that, to an engine, good moves don't really exist: you can only keep your winning chances or lose some of them.

• The score is a summary of a deep search, not a sentence. The reason a move is bad might be ten moves deep in a line you never saw.
• The same centipawn loss means different things in different positions. Lichess gives the example that losing 300 centipawns in an equal position is a major blunder, but makes almost no difference when the game is already won or lost.
• Accuracy measures soundness, not difficulty. Lichess says Stockfish "can't tell us how difficult it is to find" the best moves.

Use the engine to find the moments, then answer the why yourself before you look at the line. This order is the part the engine cannot do for you.

1. Play through the game once without the engine and note where you felt unsure or short of time.
2. Open the Analysis board and click Request a computer analysis.
3. Click Learn from your mistakes. For each flagged move, try to find a better move before asking for the solution.
4. For each mistake, write one line: what did I miss (a threat, a loose piece, a check) and what was I thinking instead?
5. Only then look at Stockfish's line, and play it out on the board until you can say what it threatens.
6. Group your one-liners across several games. A reason that repeats is worth more than any single engine line.

Lichess says Learn from your mistakes works on every game on the site, including imported games and old games, and cross-checks Stockfish against its masters database so that a move masters play is not flagged as a mistake. Steps 1, 4 and 6 are our suggested routine, not a Lichess feature.

They use different formulas. Lichess says there is no universally accepted way to compute accuracy, and different websites use different formulas, engines and analysis depths. Lichess runs the latest Stockfish NNUE server-side and benchmarks winning chances on games between 2300-rated players.

These are individual players' views from public threads, not facts about Lichess. They show why the question gets asked.

• A Reddit user: "All I see whenever I use Stockfish on Lichess are variants and a plus or negative sign."
• A Lichess forum user suggests working around it with a Study: "You could make do with the Lichess analysis board and put that into a Lichess Study. You can make notes, add variation[s], engine check..."

When you keep seeing the same kind of mistake and can't name it yourself. Then you need something that groups your games, not another single-game score.

• See the full routine in how to analyze your own chess games.
• If the same error keeps showing up, read why you keep making the same mistakes.
• For what AI explanation tools can and cannot do, see what an AI chess coach is.