How is accuracy calculated? (with an example)

When I look at this game, I don't understand how accuracy is calculated at all. If you have only book moves, lets say 6 each and you would agree to a draw, both will have 100% accuracy. However, when you look at the game below, it doesn't count the book moves at all, and even then the math doesn't add up or at least I can't make sense of it.

I know that it doesn't really matter, but I am just curious as to how these numbers are being calculated.

https://www.chess.com/a/GW7cT1oC27pzJ

Ohhhh cool

The algorythm for calculating accuracy is one of the hidden mysteries of the universe.

Nobody knows.

Why have they stopped showing the accuracy percentage does anyone know

A partial answer is that not all book moves are  best moves.  They're just moves that have been analyzed to death, and a large number of top players follow whatever variation appeals to them at the time.  For example, standard responses to 1. e4 are:  1. ..e5, 1. ..c5, 1. ..c6.  Which one is the best move?

@woton I agree to that of course, but they are still moves, they are not bad even if they are standard, so should they be disregarded? Because if you have a match in which both sides do 12 book moves in a row and the 13th move is a blunder by white after which they resign, you would get a 100 vs 0 accuracy, which is ridiculous imho.

Also you could break the book move chain by one other wrong move and then go by the book again for a few moves and then they wouldn't count as book moves, but as best or excellent moves, which would give you a higher accuracy, but a worse game to show for it.

I don't pretend to know any other solution or think  accuracy is almighty, but something is a little off there.

Somewhere people more knowledgeable about the game than I am decided what constitutes a best move and that's what's programmed into the analysis.  It's not percfect.  I usually play out endgames when my opponent resigns and I will play several variations.  Many times, I get to situations where any move that I make is labeled a "best move."  As my picky English professor once commented on one of my papers, "there can only be one best."

It’s a joke status lol.

42

your Accuracy is a measurement of how closely you played to what the computer has determined to be the best possible play against your opponent's specific moves. The closer you are to 100, the closer you are to 'perfect' play, as determined by the engine.

So unless you are cheating or are Magnus, then it will be low I guess

You should not use that terrible, offensive font, and you should not accuse people with cheating. Even as a joke.