Is there a decisive game with no mistake or blunder by either side?

Also something important to note. The inaccuracy mistake and blunder are only relating to the outcome of the game. For example you can sac a queen in a +30 position and go down to like +7 and it will only mark that an inaccuracy.

If chess is truly a drawn game from the start then there should not be any possible game that ends in checkmate without at least one mistake IE when the game goes from drawn to lost.

Oops I guess I should have said "ends in checkmate" instead of "decisive", but there are some things you just can't take back. The cat is out of the bag, the toothpaste does not go back in the tube and the bell can't be unrung. Now the topic of this lichess thread is about whether a game is said to have concluded decisively if it ends in resignation, and whether +2 or +3 eval is considered a decisive lead in a game. RIP.

Quoting myself from a few weeks ago: I once saw a game (between top GMs) where white made only one inaccuracy (black didn't make any) until the position was a tablebase loss...for black!

But IIRC then Stockfish spuriously marked black's next move as a blunder even though he was lost anyway, and white may have later blundered it back into a draw or something.

@Lidraughtsorg while supporting your post, imo because white makes the first move chess would not be a drawn game, but a white game. So technically anything that's not a white win could be considered decisive :D

@brochess no, your intention was clear enough - I misinterpreted. But the debate around decisive also turns out interesting.
Would it be ok if we also study slightly decisive games in the discussion, and pay special attention if a game is found that is clearly decisive. But I think the point is that we might not find such a game :)

For me I hope that there is no perfect game, that fish net starts at the end result working back to find the mistake / master stroke that brought around the result.

The difference between machine and human opponents: IMAGINATION. I never imagined I could beat an 1800:)

I once had an OTB game where I made 15 inaccuracies and my position was at -4

@brochess I think you could manufacture such a game on lichess by getting Stockfish to play against itself

@xK4LIBUR How did you arrive at that conclusion. Just because someone moves first does not give them the advantage maybe the entire game is a zugzwang for white. Take tictac toe, connect 4 or checkers, even though white moves he literally has no chance but to draw. (Look up pursuit evasion games there are certain positions where if the chaser moves first he has no win.)

Though your stance may make more sense if indeed white has a forced win which I don't believe nor do many GMs.

I imagine you totally confused me now, so I'll just stand corrected. I thought I was taught that all things being equal, white has the advantage, making the first move, I will re-think.

EDIT: I believe you're correct - I am actually relieved, it brings some magic back for me.

The present common belief is that chess is a draw.
The white advantage is an illusion from the previous century.
So there cannot be any decisive game without any mistakes.

Lichess analysis condider move an inaccuracy only when it losed half a pawn. So one can do lose .4 pawn per move in three moves and be in practically lost position without having made a mistake. And has happened to me. Pressing learn from your mistakes jumps to point where am -1.6 : You played well but you are about to lose the game