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.
Also called: missed opportunity
A missed win happens when you stand clearly better, the engine sees a forcing way to convert, and you play something that lets the advantage slip. It is the mirror image of a blunder: instead of ruining a fine position, you fail to cash in a great one. Typical causes include overlooking a strong sacrifice, choosing a safe move when a sharp one worked, or relaxing once you feel ahead. Tools define the label differently, so one program may call a drop from a winning position a mistake and another call it a missed win. Club players meet these constantly, because the moment of maximum advantage is also the moment of overconfidence. The common error is to move quickly when winning, assuming anything will do. A good habit is to slow down exactly when the position turns favorable, look for the opponent's best defense, and prefer moves that remove counterplay. Reviewing your missed wins is cheap training, because the winning idea was already on the board.
It sits close to 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.
Computer terms such as "Missed win" 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
A mistake is a game review label for a move that clearly worsens a position, costing a meaningful share of the advantage, though it is less severe than a blunder that throws the game away.
A blunder is a very serious error, such as leaving a piece undefended or missing a decisive tactic, that swings the evaluation so far that a good position turns bad or a bad one becomes lost.
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.
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.
Tactics training is deliberate practice at spotting and calculating short forcing sequences, such as forks, pins and mating attacks, usually through puzzles, so that these opportunities are found quickly in real games.
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.