About TrueElo

TrueElo is a chess analysis site for competitive players. It answers the question an engine will not: not what wins under perfect play, but what actually wins at your level.

An engine judges a position as if both sides played near-perfectly. Below master level nobody does. So it calls positions winning that club players routinely lose, and positions lost that they win more often than not. The gap between those two answers is what this site measures.

Where the numbers come from

The analyzer’s True Score is built from two sources. The first is the Lichess Open Database — billions of real, rated games that Lichess releases into the public domain under CC0. The second is Stockfish, which runs in your browser and supplies the theoretical evaluation.

The games are not ours. What is ours is the reading of them: keeping the ones at your level and your clock, and weighing them against the engine to get a number you can act on. Cite it as “TrueElo analysis of Lichess data”.

How the True Score is built

A move that won 60% of fifty games is a worse bet than one that won 55% of five thousand. Treat them alike and you get confident nonsense.

So we start from what the engine thinks and let the games played at your level move it. Where there are few games the engine’s view holds; as games pile up, they take over. Out comes your True Score, with the engine’s own answer printed beside it — always, because the two disagreeing is the entire point.

Moves are ranked by their Floor — the worst score they would still get, 90% confident — rather than by their headline number, so a move backed by a handful of games cannot outrank one backed by thousands on a lucky run.

What it costs

The analyzer, opening statistics, and Repertoire practice are free. Signing in with a free Lichess account tunes the numbers to your level.

Signing in reads your username and ratings and never posts to your account. You do not have to play there — a Lichess account works even if your games are elsewhere.

Who runs it

TrueElo is built and run by Aviram Kofman. Questions, corrections, and bug reports are welcome on the contact page.

See also the privacy policy and the terms of use.