Is it possible to loose a game without mistakes by checkmate ?

book moves are not considered mistakes by engines. But yes, "mistakes" were made.

Is it possible?  Not really, but there is a caveat.

If you play an opening gambit (i.e. The Smith-Morra) and then proceed to trade equal material, there is a chance it will show up as 0 blunders and 0 mistakes in the chess.com analysis tool, but you've simplified down to a pawn endgame down a pawn (thus losing).

Additionally, you have to realize that the analysis tool analyzes at whatever depth you have set (and that is limited if you are a free member).  That means that a move that isn't classified as a mistake in one analysis might be classified as a blunder when doing deeper analysis.  In short, do not take it as gospel, but as a guide.  There are also times where it will classify a move as inaccurate or a mistake when it is the most human way to convert a position (this often happens when you are in a winning position and your opponent leaves more material hanging - the computer wants to continue collecting material when you can just as easily simplify the position into a winning endgame, which is the human approach).  A good example of this is when the computer will point out "Here you missed a forced mate in 10" when you had a 2-move tactic to win their queen and then simplify into a winning endgame.

Thanks for your analysis nklristic. I can see that I made some mistakes now. Maybe the analysis depth I used was low because I have a free account. Here is another game that the computer apparently said contained no blunders, mistakes or inaccuracies, but again I lost by resignation.

[Date "2021-03-25"]

[White "DanielArnett"]

[Black "JohnGregoire"]

[Result "0-1"]

[WhiteElo "1596"]

[BlackElo "1927"]

[TimeControl "blitz"]

[Termination "JohnGregoire won by resignation"]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 d6 6. Be2 e5 7. Nf3 Be7 8. O-O O-O 9. Be3 Be6 10. h3 d5 11. exd5 Nxd5 12. Nxd5 Qxd5 13. Qxd5 Bxd5 14. Rfd1 Rfd8 15. c4 Be6 16. Ng5 Bxg5 17. Bxg5 f6 18. Be3 Kf7 19. b3 Ke8 20. Bc5 Rxd1+ 21. Rxd1 Rd8 22. Rxd8+ Kxd8 23. Bf8 g6 24. Bg7 Ke7 25. Bf3 Bf5 26. Bxc6 bxc6 27. g4 Bb1 28. a3 Ba2 29. g5 fxg5 30. Bxe5 Bxb3 31. c5 Ke6 32. Bb8 a6 33. Kg2 Kf5 34. Kg3 Bd1 35. Bd6 g4 36. h4 h5 37. Be7 Ke4 38. Bd8 Kd4 39. Bb6 Kc4 40. Kf4 Kb3 41. Kg5 Bc2 0-1

You're welcome. I generally don't take those blunders, mistakes and inaccuracies generated by chess.com report too seriously. As you've seen, that Fool's mate game will show 100 accuracy because all the books were book moves. It is much better to look at the move and see if there is some shift in the evaluation. If the shift is 0.1, 0.2, maybe even 0.3 then that is probably fine. But if the shift is 0.6, 0.7 then that is already an inaccuracy, and it might be a good idea to try to understand why. 

I do generate reports to see how many blunders and inaccuracies are there, but it is mostly for fun. I look the game more thoroughly off site with a free tool. As I prefer longer games, I do tend to look every one of them afterwards.

This second game is more interesting. I've run the on site analysis and it shows one blunder each side and a few mistakes and inaccuracies, but I will look at it more thoroughly now because the story of this game is as follows:

You got to the endgame with equal position with some trades, and then in the endgame the opponent got a winning position in the end. 

Mistakes in the endgame are much more subtle, and a harmless looking pawn move can be the decisive mistake. 


For instance, here, it is pretty subtle. Before move 30 you were a bit worse, but this is opposite color bishop endgame, so it is probably holdable. On move 30, you've taken the pawn with Bxe5. That resulted in you having 2 isolated pawns. It was probably better to play b5 and then if he takes your c pawn, you take his and you continue the game 1 pawn down but with less weaknesses. 

Here is a bit better analysis:

Now, it took me a while to do this, but if I was playing OTB chess, I would certainly look at this endgame for a few hours. Even someone as weak as myself can draw some conclusions form it. And if you get a single idea friom such analysis, it is well worth it.

Of course, as I am just a hobby player, I wouldn't look much more than this.

This is just another way of asking 'Is there a way to play a game of chess such that you win regardless of what moves the opponent makes'  i.e. 'Have we solved chess'?

The answer to that is definitely no!

That would unfortunately be yes, as this match proves...

https://www.chess.com/analysis/game/live/90612636279?tab=review

There was only two inaccuracy past move 20, mate was unavoidable though...

That game does not prove you can lose without making a mistake as there were several mistakes made by both sides.

No. Every game that ends in checkmate must contain an odd number of mistakes.

if you read the title, he clearly said that the mistake or blunder must lead to checkmate.

Mistakes can be in many forms, including losing material.

Title: "Is it possible to loose (sic) a game without mistakes by checkmate ?"
Answer: no. If a game is lost by checkmate, then there must be an odd number of mistakes.
If a game is without mistakes, then it cannot end in checkmate.

Hi.

No, it isn't. Chess is a draw with good play by either side.

Side A could make five mistakes, that lost various pawns and pieces. Side B could then make one mistake which resulted in checkmate given best play by both sides.

Result: even number of mistakes and a checkmate.

Conclusion: Thesis rejected by non-empirical analysis.

@81

A makes 1 mistake (?), now B is winning. A cannot make more mistakes: you cannot make a mistake in a lost position. Now B makes a blunder or double mistake (??) that loses his won position to checkmate.

Result: 1 + 2 = 3 mistakes which is an odd number.

Conclusion: thesis confirmed.

Yeah I think resignation is the only way. I think?

What if you and your opponent are playing perfectly? You're on the black side, and he/she or another player is on white. If both players play in a way that leaves a 50% win rate, would it result in a guaranteed stalemate?

Yeah

yes because if ur opponent plays spot on and u play good move per turn

You: 70%

Them: 95%

we all know who's winning

bro not what I said

ChessAGC_YT bros on every forum no offence