The chess.com analysis thing is very lenient (and a bit mysterious with how it calculates the percentage).
https://www.chess.com/forum/view/game-analysis/the-analysis-tool-cant-count?page=1
https://www.chess.com/forum/view/general/91-accuracy-are-you-mocking-me
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Even so, objectively your accuracy will partly depend on how sharp the game is. A low skilled player could play very accurate moves in a short boring game (often a french exchange or slav exchange between low rated players will result in a high accuracy score) while a GM might blunder in a sharp KID or Najdorf...
... which leads to an interesting facet of chess many players aren't aware of, which is posing practical problems for your opponent. An experienced player understands that in many positions there are many equally good options. Think of an endgame tablebase where maybe half a dozen moves win, half a dozen draw, and the rest lose.
So in a game, let's say 2600 vs 2400 and the GM needs to win, the GM may play "inaccurate" moves for the sake of posing more problems for his lower rated opponent. A system like chess.com's may call the move inaccurate even if the "true" evaluation (win, loss, or draw) is not changed.
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So to answer your question, when two GMs want to draw, sure, their game may be 99% (or 100%) accurate, but between two GMs who need to win (due to the tournament situation) the game may have many inaccuracies and errors, some of which will be played on purpose.
I'm just curious, how high is GM level play accuracy? I'm guessing 99% range.
I play a few games here and there. When I do the computer game analysis, I get a big range depending on the game...somewhere between 20% to 95% range (yes, I have games where I make lots of mistakes, even blunders). I'm thinking if someone like me (beginner, low level) can get 95%, then GMs must pretty much be in the 99% accuracy for nearly an entire game until the very last move when someone pulls out a win. Since a lot of games end in a draw, that must mean GMs could be 99.99% accurate nearly every time they play.
Anyone have thoughts on how accurate GM are and how to achieve this level of play? I already do tactics everyday but I know I could be doing more things besides tactics.
Does anyone have statistics or insight on this?