Universal rating • page 1/1 • General Chess Discussion • lichess.org

JA10306

#1

Why are all the ratings different between Lichess Chess.com and FIDE etc....why can they all use the same system?

SimonBirch

#2

In an ideal world this would be great xxx

SimonBirch

#3

I think you meant can't xxx

petri999

#4

Even if everyone used same method for calculating becasu different pol of people attending the ratings would diffe. So no gaib here to be observed.

lizani

#5

How could this ever work?
Chess is played in multiple formats - correspondence, classical, rapid, bllitz, bullet, 960 to name just the most popular.
Chess is played in multiple platforms - your local club, national tournaments, FIDE tournaments, ICCF for correspondence, online.

Each of these is a different world and there is no mixing between them. Yes, they involve the same players but their ratings are divergent, sometimes by a large amount. For example, Gukesh is classical world champion with a live rating of 2777, #5 in ranking, but only 2615 in blitz and ranked #90.

People amuse themselves by converting one rating to another with equations like x = (-b ± √(b2 - 4ac)) / (2a) but these are meaningless. View the plethora of ratings as an opportunity that gives you bragging rights. You can say 'Yes, I am a patzer but in bullet I am GM level' and so on.

How could this ever work? Chess is played in multiple formats - correspondence, classical, rapid, bllitz, bullet, 960 to name just the most popular. Chess is played in multiple platforms - your local club, national tournaments, FIDE tournaments, ICCF for correspondence, online. Each of these is a different world and there is no mixing between them. Yes, they involve the same players but their ratings are divergent, sometimes by a large amount. For example, Gukesh is classical world champion with a live rating of 2777, #5 in ranking, but only 2615 in blitz and ranked #90. People amuse themselves by converting one rating to another with equations like x = (-b ± √(b2 - 4ac)) / (2a) but these are meaningless. View the plethora of ratings as an opportunity that gives you bragging rights. You can say 'Yes, I am a patzer but in bullet I am GM level' and so on.

StanFurd

#6

People amuse themselves by converting one rating to another with equations like x = (-b ± √(b2 - 4ac)) / (2a)

Conversions are indeed possible. A too-common mistake is in using the quadratic formula for a task that requires Riemannian manifolds.

> People amuse themselves by converting one rating to another with equations like x = (-b ± √(b2 - 4ac)) / (2a) Conversions are indeed possible. A too-common mistake is in using the quadratic formula for a task that requires Riemannian manifolds.

EmaciatedSpaniard edited

#7

@JA10306 said in #1:

Why are all the ratings different between Lichess Chess.com and FIDE etc....why can they all use the same system?

Chess.com uses glicko, lichess uses glicko-2. But the more important point is that these ratings systems are a relative ranking within the group. So, if you have two groups and one is a group of grandmasters and one is a group of beginners and they each play using the same ratings system (but the ratings are determined only from play within the group), 1500 in one group is not the same thing as 1500 in the other.

Even when you have some overlap of players, as is probably the case for chess.com and lichess, (and even if both used the same system), the ratings can't be directly compared. This is because there is a different range of abilities represented in each group.

edit: thanks for @petri999 for pointing out chess.com uses glicko, not elo.

@JA10306 said in #1: > Why are all the ratings different between Lichess Chess.com and FIDE etc....why can they all use the same system? Chess.com uses glicko, lichess uses glicko-2. But the more important point is that these ratings systems are a relative ranking within the group. So, if you have two groups and one is a group of grandmasters and one is a group of beginners and they each play using the same ratings system (but the ratings are determined only from play within the group), 1500 in one group is not the same thing as 1500 in the other. Even when you have some overlap of players, as is probably the case for chess.com and lichess, (and even if both used the same system), the ratings can't be directly compared. This is because there is a different range of abilities represented in each group. edit: thanks for @petri999 for pointing out chess.com uses glicko, not elo.

petri999

#8

Chess.con uses glicko. Fide andmost national rating use Elo

V1g1yy

#9

@lizani said in #5:

People amuse themselves by converting one rating to another with equations like x = (-b ± √(b2 - 4ac)) / (2a) but these are meaningless.

I remember that from 7th grade like it was yesterday. They burned that into our minds. A lifetime later, I have never one time ever used it in actual practice. Talk about wasted storage space in the brain... I want my space back, lots of other meaningful stuff has leaked out because there wasn't room for it now. :D

@lizani said in #5: > People amuse themselves by converting one rating to another with equations like x = (-b ± √(b2 - 4ac)) / (2a) but these are meaningless. I remember that from 7th grade like it was yesterday. They burned that into our minds. A lifetime later, I have never one time ever used it in actual practice. Talk about wasted storage space in the brain... I want my space back, lots of other meaningful stuff has leaked out because there wasn't room for it now. :D

h2b2

#10

@V1g1yy said in #9:

I remember that from 7th grade like it was yesterday. They burned that into our minds. A lifetime later, I have never one time ever used it in actual practice. Talk about wasted storage space in the brain... I want my space back, lots of other meaningful stuff has leaked out because there wasn't room for it now. :D

off topic, but, learning maths as a kid shapes our brains and makes us better thinkers in general that helps with all aspects in life.

@V1g1yy said in #9: > I remember that from 7th grade like it was yesterday. They burned that into our minds. A lifetime later, I have never one time ever used it in actual practice. Talk about wasted storage space in the brain... I want my space back, lots of other meaningful stuff has leaked out because there wasn't room for it now. :D off topic, but, learning maths as a kid shapes our brains and makes us better thinkers in general that helps with all aspects in life.