Guide
What Is ACPL in Chess? (Average Centipawn Loss Explained)
ACPL (average centipawn loss) measures how far your moves deviate from the engine's best line. Learn what good ACPL looks like by rating level.
Updated 2026-06-15 · Part of improvement series
ACPL in one sentence
ACPL — average centipawn loss — is the average amount of evaluation (in centipawns) your moves cost compared to the engine's top choice. Lower is better: an ACPL of 0 would mean you played like Stockfish every move; that never happens for humans.
Rough ACPL benchmarks by level
Use these as orientation, not law — time control and position type matter:
- 2600+ GM: often under 20 in classical
- 2200–2400 master: roughly 20–35
- 1800–2000 strong club: roughly 35–55
- 1400–1600 improving adult: roughly 55–80
- Under 1200: often 80+ with large spikes on blunders
ACPL vs accuracy percentage
Many sites convert ACPL into an accuracy score (0–100%). They use similar underlying data but different formulas. Two players with the same ACPL can look different if one made a single huge blunder and the other made many small inaccuracies.
Track both if available: accuracy is intuitive for comparing one game; ACPL is better for trends over many games.
How to improve your ACPL
Cutting ACPL is mostly about eliminating blunders, not finding brilliancies. Prioritize hanging pieces, one-move tactics, and forced sequences you miscalculated. MAZChess tags blunders and mistakes per move and rolls them into your insights dashboard over time.
Frequently asked questions
- What is a good ACPL for blitz?
- Blitz ACPL is naturally higher than classical — expect 20–40 cp more at the same strength. Compare blitz to blitz, not blitz to rapid.
- Does ACPL punish slow moves that are still best?
- No. ACPL measures evaluation drop from the best move, not speed. Time management is separate from centipawn loss.