Performance Rating Of a Game

It would be nice if performance rating is added to each game a player have played in the same page of analysis board. So, in addition to accuracy and other statistics, a player can see the performance rating of a game he/she is analysing.
Chess.com has this new feature in the review page.
I know in a Swiss tourney, Lichess displays an overall performance rating from the accumulation of the games that a player has been playing in the tourney.
But, it would be nice if the same feature is provided to a regular (non-tourney) game too.

It's easy to calculate:

You win: plus infinity (or approximately opponent's rating + 500)
You lose: minus infinity (or approximately opponent's rating - 500)
Draw: Your oppoent's rating

If chess.com has it different, it's not a rating!

Performance rating for a single game is nothing more than . . . . a performance.

Performance rating of a tournament is simply based on your results in the tournament. Like, if you score 50% against an opposition with average rating of 1500 your performance rating in the tournament is 1500.

As such, a performance rating of a single game simply doesn’t make any sense at all. I assume what chess.com does - if they really assign a rating to a game - is some kind of statement a la “in this game you played like a 1800 rated player”. If that assumption is correct then I doubt this is actually a useful information, as there are very different player profiles to achieve certain ratings, and for example average centipawn loss can vary drastically between players of the same ratings. But maybe my assumption about what chess.com does is wrong anyway and they are more sophisticated. In any case, before discussing how useful such a performance rating assignment would be some more details would be required how it should be determined. Just getting a number that looks cool is probably not worth it.

Not to mention that it would lead to even more baseless cheating accusations; accuracy is bad enough already

@MentalFugues said in #3:

Performance rating for a single game is nothing more than . . . . a performance.
Of course it is a performance. But what I want is a measure to describe the performance : how it likes in terms of rating.
For example, in a game, a player performance is measured such that he is considered to play like a 2000 player, while his opponent has performance of 1700.
The example mentioned by user @M0r1 above is exactly I mean too.
However, I am not sure what actually the performance rating on chess.com is.

@M0r1 said in #4:
I think we have heard expressions like : "he plays like a NM, FM, IM, GM, etc", when describing someone's performance. We can consider it as a qualitative way to describe the performance.
What I want here, as provided on chess.com, it gives a quantitative way to measure the performance.
I am not sure this is useful, but at least, players will be glad to see this as a kind of appreciation given to them for all of their efforts in that game.
Maybe this feature can be provided as a preview release. People can then evaluate it, giving feedback whether it is a nice addition or not, until Lichess makes the final decision.

@Cedur216 said in #5:

Not to mention that it would lead to even more baseless cheating accusations; accuracy is bad enough already
For now, I don't expect or don't consider the downside yet. I only expect things I mention in my reply to other users.
Of course, it needs evaluation.

I think chess.com must have reasons for providing that feature.
Well, maybe I will search on its forum about it later.

@LexDev said in #9:

I think chess.com must have reasons for providing that feature.
Well, maybe I will search on its forum about it later.

That reasons are solely marketing-related

I'm pretty much sure that there are people complaining "my 1200 opps play like 1800s all the time and chesscom doesn't care" ... pls don't bring this here, thanks.