The results page on Chess Cheat Detector has changed. The move timeline no longer colors a move red just because it was the engine's top choice. Each move is now colored by how commonly players at that rating play it.
What was confusing
The old timeline colored each move by how it ranked against the engine: red for the top choice, orange for the top 3, yellow for the top 5, and green for anything else. The score at the top of the page used the same colors, from green for Low to red for High.
That made the timeline look like a tally. A player sees a High score in red, then a timeline full of red moves, and concludes the score is counting them. Obvious moves would previously be colored red if they were also the top engine move.
This made it look damning, but it wasn't how the score works. The model never judges single moves. It scores the whole game, and it weighs each engine match against how likely a human at that rating is to find the move. A forced, obvious block counts for very little, but the timeline just didn't show it.
What changed
- Colors show how common a move is at the player's rating. Each move is now marked Common, Plausible, Uncommon or Rare, using the same neural network the model uses to predict what players at each rating play. Obvious moves are now Common, and green, even if they are the top engine move.
- Bar height still shows the engine match. Taller bars are closer to the engine's top choice. A tall red bar is a top engine move that players at that rating rarely find, which is what stands out to the model. A short red bar is a rare move that isn't one of the engine's choices, which is usually a mistake rather than a sign of engine use.
- Grey still means unscored. Grey moves aren't counted in the score, because they're opening or forced moves.
- Games without ratings are shown in blue. About 15% of games come without ratings, or from anonymous Chess.com games where the ratings aren't reliable. Without a rating, there's no way to say how common a move is, so those moves are blue rather than colored by rarity.
- The score is labeled. The number at the top is now marked "ML suspicion score", with a short explanation of what goes into it. It's a probability from the model, not an accuracy figure.
What didn't change
The model itself is untouched, although a new version is coming soon. Only the way the results are shown has changed. Analyses run before this change didn't record how common each move was, so their timelines show blue.
Got a game you want to look at again? Paste it in and see the new timeline.