Know why you lose.
Not just how many centipawns.
The most precise free chess profile analyzer on the Internet. Powered by the original MQ-Chess (Loss Index) algorithm weighing decision complexity ln(N_legal+1) against win-chance deltas.
Why Average Centipawn Loss (ACPL) Fails
Traditional chess analyzers compute raw average centipawn loss across all moves. MQ-Chess measures true Win Chance Delta (ΔW) weighted by Decision Complexity ln(N_legal + 1).
The Problem: ACPL treats both scenarios identically! It penalizes a player who is up a queen for making a harmless move just as harshly as a player who blunders their queen in an equal game.
The MQ Solution: Converts evaluation to Win Chance via sigmoid σ(cp) = 2/(1 + e^(-0.003624 * cp)) - 1 and weights moves by legal options ln(N_legal + 1).
Engineered for Competitive Precision
Zero clutter, zero vanity metrics. Everything designed to turn your game data into actionable chess progress.
20 Original Metrics
Opening Stability, Pressure Resistance, Time Collapse, Tilt Index, Conversion Score, and 15 more objective performance indicators.
PGN Drag & Drop Analyzer
Upload any raw PGN game for instant move-by-move evaluation graphs, critical blunder maps, and MQ contribution breakdown.
Head-to-Head Compare Mode
Compare Magnus vs Hikaru or yourself vs your rivals across accuracy, openings, time scrambles, and endgame technique.
Algorithmic Recommendations
No AI hallucinated advice. Pure deterministic mathematical thresholds that deliver concrete training actions.
Time Collapse & Tilt Tracking
Identify exact time-pressure thresholds where your calculation filters break down and post-loss performance drops.
Player DNA Radar
A 6-axis visual radar measuring your Attack, Defense, Opening, Endgame, Time Management, and Tactical Vision.
Frequently Asked Questions
Everything you need to know about the MQ-Chess engine and metrics.
Join the MQ Chess Lab
Be part of our open-source chess analytics community. Vote for new metrics, test early engine builds, and discuss decision complexity math directly with developers.