Up to which time control does the game acuracy noticeably increase ?

from bullet / blitz to rapid the game acuracys increase alot , so is maybe 10,5 /15,10 the point where after that acuracy improvement slows down ? ( i would imangine that 30 min + brings only smaller increases in acuracys )

45-60 min at my level, maybe as much as 90-120 at a higher level? And in the highest level, I have to think correspondence will be nearly perfect in a hypothetical world where engines aren't used in competitive correspondence chess. Grandmasters often spend an hour on a move, so accuracy would probably continue to go up until correspondence.

online correspondence chess does not allow engine and indeed the accuracy is higher than classical

here are my stats, although note that my recent lichess correspondence games are against players who lost relatively easily. My chess.com correspondence accuracies generally land from 80% to 100%

"Up to which time control does the game acuracy noticeably increase ?"

• Up to 5 days / move ICCF correspondence: 100% in finals.

@tpr said ^

"Up to which time control does the game acuracy noticeably increase ?"

• Up to 5 days / move ICCF correspondence: 100% in finals.

That's engines evaluating engines. How could it not be 100%?

@tpr said ^

"Up to which time control does the game acuracy noticeably increase ?"

that suprised me . how can one spend more than 10 min analyzing a move without forgetting some of it mid analysis ?

"how can one spend more than 10 min analyzing a move"

• Practice. Grandmasters sometimes think an hour on a move.
  In a game against Szabo at Budapest 1950, Keres thought for 2 hours about move 5.
  In the time with adjourned games players and their seconds analyzed the whole night.

@tpr said ^

"how can one spend more than 10 min analyzing a move"

• Practice. Grandmasters sometimes think an hour on a move.
  In a game against Szabo at Budapest 1950, Keres thought for 2 hours about move 5

wow that is very impressive , but it has to be very boring, i would probably fell asleep if i tried these extreme long classical games

Honestly my accuracy in rapid or blitz is kinda low, I like to play messy/sharp openings and so many opportunities are missed. In bullet if both play a premove setup and just shuffle pieces and trade later the accuracy would be pretty high.

Here is the game
https://www.chessgames.com/perl/chessgame?gid=1072293