0 inaccuracies ≠ cheater

Having a game with 0 inaccuracies doesn't mean that the one who played the game is a cheater. Why? Because having 0 inaccuracies doesn't mean that the one who played the game always knew the BEST move. It means that the one who played the game didn't make any mistakes. So sometimes this person chose the second best move and it was still good enough to not be considered an inaccuracy. Maybe the name "inaccuracy" is misleading as players with games with 0 inaccuracies actually made slight mistakes.

Sorry if I wasted your time and you already knew this, but there are many players who don't know. Share this to those people. Maybe this can reduce random accusations.

Threshold for inaccuracy in lichess analysis is pretty high. So high that you can even lose without making one

Depends on the length of the game and the player's rating. If a 1500 rated player is playing an opening trap or some theory line or something, yeah, you can probably get a perfect game that lasts 20 moves. I would be very skeptical if the same player were getting a 0-0-0 game that lasted 100 moves.

I would say it depends on the game and players rating if it's likely a cheater. I'd be less suspicious of GMs if they have a flawless performance than other players. I'd also be less suspicious over a miniature than some insanely complex game. Also I wouldn't call anyone a cheat based on just one game for the most part. I'd want at least a few very suspicious games to make sure. It's more about "computer moves" than low number of errors. It's a pattern of behavior. Another thing to look at is move times. If they move in a fairly rigid interval then it may be an engine. (For instance thinking the same amount on a position with 1 legal move as one with all the pieces on the board, a lot of tension where there seems to be a half dozen reasonable moves)

TL:DR 0 0 0 does not mean cheater automatically there are many factors.

Sometimes you just get that feeling - it is a computer or kibbitzer just playing to a level even when it makes a mistake. But what is the point? Play in public and practice in private.

In believe access to an analysis board increases the elo by about 250. So I would expect to play at about 1550 in correspondance.
The odd game with computer help won't make too much difference but it may play on your conscience.
The starting position is balanced and master games keep it that way. It is also true to say there are often a hand full of alternatives in most positions.

Well... When a player with 1100 rating outplays you with some strong moves in a row in 1min. bullet game... It would be ok for 2000+, but there were too much cheaters for a tournament just ended... So i decided to abandone this hopeless action.

@Lubitel166 That is exactly what I am trying to refute. Does anyone read my text`? You don't NEED to be 2000+ to play flawless games! I did it myself many times and I am FAR AWAY from 2000. Even a 1500 guy can play flawless games. When you are attacking it isn't difficult to find winning moves!

@Lubitel166 1100 in bullet means nothing - the player with a 1100 bullet rating could legitimately have been the same strength as you. I don't play bullet, but my rating on here id currently under 1700, yet I have outplayed titled players and 2200+ lichess players more than once - it just doesn't happen often enough for it to have an effect on my rating. Many people with a much higher rating than me are actually the same strength, but don't blunder - especially in fast time controls, as I would not be surprised at beating a 2200 bullet player in a classical game.