# What does “Precision: White = nn%, Black = nn%” mean in a game broadcast by chessbase.com?

The game "Salgado L, Iván vs Arroyo R, Jesús, 83rd ESP-ch 1-0", shows this annotation after the last move:

Precision: White = 93%, Black = 18%.

What does that phrase mean?

It surely is a measure of the quality of play, the deviation of the game from a "perfect game", as understood by the engine used in the analysis. A perfect move will lose zero units of measure.

I couldn't find a chessbase source, but here it is a similar question on lichess, in which the unit of measure is called a centipawn:

https://lichess.org/qa/103/what-is-average-centipawn-loss

Centipawn loss could also be expressed as percentage, but as your question is about precision, they should be the opposite amount. In your example for white, a precision of 93% equals 7 centipawn loss (7% of inaccuracy).

• tl;dr : It doesn't mean much. :) – Evargalo Sep 11 '18 at 8:52
• @Evargalo The answers in that thread are not too long. Do you mean that precision or centipawn loss measures don't mean much? – Daniel Alfredo Sottile Sep 11 '18 at 13:59
• Yes, that's what I mean, I think one shouldn't worry too much about these measures, especially precision aggregated on a whole game. But my comment was rather tongue-in-cheek, don't take it too seriously... – Evargalo Sep 11 '18 at 14:36
• Could it be that precision is the percentage of moves that coincide with some engine, running under some unknown parameters? – djnavas Sep 11 '18 at 18:01
• @djnavas Do you mean the percentage of moves that coincide exactly with the best move according to that engine? I don't think so, because it would be even more useless, as Evargalo said. – Daniel Alfredo Sottile Sep 12 '18 at 10:42