Converting Chess.com to Lichess Ratings: A New Data-Driven Method

Actually, this is interesting, and my case fits almost perfectly, I have 1450 rapid on chesscom, and I "feel" that my real rapid rating/strength is around 1650 - 1700 here on Lichess
(although currently the rating much lower, but that's a different story)

But I have to say that I saw players with lower average accuracy than me, but they are much stronger, I remember seeing one player's insights and he had 63% average accuracy in rapid after thousands of games, and I was surprised, since mine is 70%+, but his ratings were close to 2000s, while I play like s##t ...

And I'm still confused, I know legit players who can beat me up to 67% of our games, but my insights show that I have significantly lower ACPL and higher average accuracy ... And I still don't understand how so (No, they are 100% clean real people)

That's great if it fits your case well, thanks for the feedback!
This study is mainly reliable on an individual level for saying "if you are X rating on Chess.com, you should be around Y rating on Lichess."
BUT it doesn't mean "if you have X% accuracy, then you are Y rating." On an individual scale, that doesn't work.
The variance between playing styles changes a lot.
Like you said, you can have a higher average accuracy than another player but still be weaker than them.

@Enlightenmania2022 said in #11:


> But I have to say that I saw players with lower average accuracy than me, but they are much stronger, I remember seeing one player's insights and he had 63% average accuracy in rapid after thousands of games, and I was surprised, since mine is 70%+, but his ratings were close to 2000s, while I play like s##t ...

It could just be that he was sh## at the game as well, and maybe even worse than u at like 1200, but then improved up to 2000

A note of pedantry. I noticed throughout you refer to "Lichess Elo", but what you really mean is Lichess rating. Elo is a rating system but Lichess doesn't use it, rather it uses Glick-2. I don't know what system Chess.com uses, but if it's not Glick-2 then that's a primary reason why we have to convert in the first place.

Players’ Elo ratings on Lichess and Chess.com should be the same. And of course, the Elo calculation system should also be the same. Because classical chess is classical chess everywhere in the world.

My solution proposal: Chess.com and Lichess could collaborate and allow accounts to be linked. That way, it wouldn’t matter where you play — the Elo rating would appear the same on both platforms.

However, this doesn’t seem very likely. At the very least, it could be offered as an option for new players (“link your accounts”). For existing players, it could be optional too — “you can link if you want, your Elo will be matched with Chess.com.” In that case, if a player’s Chess.com rating is lower than their Lichess rating, their Lichess Elo would naturally drop, or the opposite could happen.

For already registered players, another option could be this: whichever platform a player has played more games on, that rating could be transferred to the other platform. This way, nobody would have issues and the chess world would be better.

The definitive solution is for the two platforms to collaborate and synchronize accounts. There’s no other way.

I enjoy playing on Lichess, but it frustrates me when a player with 1200 Elo on Chess.com checkmates me, while I have 1500 Elo on Lichess. In that case, either I’m not really a 1500 Elo player, or that Chess.com player isn’t really 1200 Elo.

acording to your calculations im supposed to be 1850-1900 on chess with the rating i have on lichess but i barely have a rating 1700 on chess.com with2050 on lichess
and aboth accounts have not more 2-3 months of age difference and i use both in the same frequency

@BinWOLT said in #15:
> Players’ Elo ratings on Lichess and Chess.com should be the same. And of course, the Elo calculation system should also be the same. Because classical chess is classical chess everywhere in the world.
>
> My solution proposal: Chess.com and Lichess could collaborate and allow accounts to be linked. That way, it wouldn’t matter where you play — the Elo rating would appear the same on both platforms.
>
> However, this doesn’t seem very likely. At the very least, it could be offered as an option for new players (“link your accounts”). For existing players, it could be optional too — “you can link if you want, your Elo will be matched with Chess.com.” In that case, if a player’s Chess.com rating is lower than their Lichess rating, their Lichess Elo would naturally drop, or the opposite could happen.
>
> For already registered players, another option could be this: whichever platform a player has played more games on, that rating could be transferred to the other platform. This way, nobody would have issues and the chess world would be better.
>
> The definitive solution is for the two platforms to collaborate and synchronize accounts. There’s no other way.
>
> I enjoy playing on Lichess, but it frustrates me when a player with 1200 Elo on Chess.com checkmates me, while I have 1500 Elo on Lichess. In that case, either I’m not really a 1500 Elo player, or that Chess.com player isn’t really 1200 Elo.
the elo in these platforms dont really matter and the international is ofcourse going to be harder than online platform
and if you transfer your lichess rating to your chess.com then you'd be overated for your playing and vice-versa you would be underatedplus joining both platforms is not going to be convienient for thecreator of the platforms tell me what do you think is better chess.com or lichess.org/? the debate still continues
dont take it as if im against you though just saying though it would be good for us like you said but still

Great post.
Now it would be amazing if it was possible to scrap the fide data and compare FIDE elo with Lichess/chess.com elo.
Some users have their real name and FIDE elo on their profile, if you find them with a script and could compare data... it'd be amazing

PS: just a suggestion for the future if you accept the challenge ;)

GPT, statistics image again..

I don't know much, but i heard its a difference of 300 of an avg.
lichess have higher rating by 300 avg of chess.com
especially if i talk about blitz or rapid chess.
though i am not sure.