Winning chances
Winning chances are an estimate of how likely each side is to win from a position, often converted from the engine's evaluation into a percentage so that the same advantage reads differently at different levels.
Also called: win probability
An engine's evaluation, such as plus two, is not a probability. Winning chances try to translate it into one. The idea is that the same material edge matters differently depending on the position and the players: a pawn up in a sharp middlegame between club players is worth less in practice than a pawn up in a clean endgame. Tools differ in how they make the conversion, and some use ratings of the players in the formula, so two programs can show different percentages for the same position. Winning chances also explain why a large drop in the raw evaluation sometimes barely changes the percentage: a position that is already totally winning does not become more winning. The common mistake is reading the percentage as a guarantee. Practical factors such as time, complexity and nerves still decide real games. A good habit is to use winning chances to judge whether a move truly mattered. If it changed the percentage very little, it was probably not the lesson of that game.
It sits close to Missed win. A missed win is a game review label for a move that fails to take a clearly winning continuation, so a decisive advantage shrinks to something much smaller or disappears entirely.
Computer terms such as "Winning chances" are most useful next to a coach who reads your games with you, which is how a first lesson with George Li works.
Related terms
An evaluation is a numerical judgment of who stands better in a position, usually given in pawns from White’s point of view, where positive favors White and negative favors Black.
A centipawn is one hundredth of a pawn, the small unit engines use to report evaluations, so a score of 150 centipawns means the engine thinks one side is about one and a half pawns better.
The evaluation bar is a vertical or horizontal gauge beside the board that shows, with a bar of black and white, which side the engine thinks is better and by roughly how much.
A missed win is a game review label for a move that fails to take a clearly winning continuation, so a decisive advantage shrinks to something much smaller or disappears entirely.
A game review is an automatic engine pass over a finished game that marks each move, shows how the evaluation changed and points out the turning points, mistakes and missed chances.
Guides that go further
What to decide first, the questions to ask, what a first lesson should show and the red flags to avoid.
How much does chess coaching cost?
Published rates for private, group and subscription chess coaching, with the source and the date of each.
A game review, a read on your level and a written study plan from George Li.
Want to spot this in your own games?
A first lesson starts with your games: George reviews them and builds a study plan around what he finds.