Stockfish reports positions with numbers like +0.30, -1.20 or M5. The notation is compact, but it hides several assumptions. Reading it well is the difference between using the engine and being used by it.

Centipawns

A centipawn is one hundredth of a pawn. +0.30 means the engine thinks White is ahead by roughly three tenths of a pawn with best play. -1.20 means Black is ahead by about 1.2 pawns. A score near 0.00 means the engine sees a balanced position.

These numbers are not linear. The difference between +0.30 and +0.60 is not the same as the difference between +5.00 and +5.30. Once one side is winning, small changes matter less.

Mate scores

M5 means the engine sees a forced mate in five moves for the side to move, assuming best play. A negative mate score means the side to move is getting mated. Mate scores are usually more reliable than large centipawn scores, but only after the engine has verified the line.

Whose perspective is it?

Most analysis tools display evaluations from White's point of view, even when Black is to move. Some engines and APIs report from the side to move. Always check the convention before comparing numbers. ChessUrge stores the white-perspective evaluation and also shows the side-to-move score in the engine panel, so the two never get confused.

What +0.30 does not mean

  • It does not mean White is winning. Club players can lose from +1.00 regularly.
  • It does not mean the position is easy. A small edge can require precise technique.
  • It does not mean the move you played is bad. The evaluation is a property of the position, not a grade for your last move.

Use the line, not just the number

Click through the principal variation. Ask what the engine is trying to achieve: a pawn break, a piece trade, a king walk, a tactical resource. If you cannot explain the plan, the number is not useful yet. Run a second line with MultiPV to see the alternative plans.

For a deeper read, use the analysis board or review a full game in the library. The evaluation is the start of the question, not the answer.

Try it on a real game

See the whole game, not just the blunder.

Choose a review depth, see the maximum cost, and get move-by-move accuracy with blunder, mistake and inaccuracy markers.

Open the library