Chess rating system

Who's Philip?

The paper is pretty thorough and easy to follow.  But if you want to the approximate version, as applies to most situations, it is as follows:

New Rating = Old Rating + k x ( Outcome - Expected Outcome) + Bonus term.  k factor is a function of rating and number of games played.  For a 1000 rated kid who has played 20 rated matches, k is on order of 55 - 65 I think.  The Outcome is 1, 0, or 0.50.  Expected outcome a function of the difference between the ratings of the 2 players:  P(win) = 1 / ( 1 + 10^(-Rating Diff / 400 ).

chess rating = no points to use

lol 125 pages in answer to a simple question... gotta love chess.com XD

125 replies provides a fuller answer to the OP

right kaynight?

i was just checking out the global ratings (i know, pretty pathetic too much time on my hands) and i noticed on the rapid board the top two highest rated players have no games credited to them, ie both 0/0/0. How does this happen?(

The site probably assigned ratings in the time control based on real OTB ratings or computed ratings in the case of the KomodoEngine account. And they haven't played games in that time control.

I was thinking about it .

I was wondering if anyone could help me with this question - what type of games are represented by things such as 30|0 or 15|5? Thank you in advance.

https://support.chess.com/customer/en/portal/articles/1444850-how-do-the-time-controls-work-in-the-live-chess-

Thank you, Mr. Stahl

hello people

Because the stat is percentile not percentage.

https://en.wikipedia.org/wiki/Percentile

A statistical percentile doesn't work like that. The ratings are broken up into bands and a range of ratings can fall into the same percentile band.

https://www.chess.com/leaderboard/live

The percentile rank is based on which rating band you fall into on that graph, essentially. The 1400 band easily looks like it could fall near the 70 percentile band, though I don't know how many bands are actually used for the calculation.

No.

He is not better due to a better rating. His rating is better due to his better play.

Sounds the same but isn't. And on the other hand comparing a rating doesn't gives you an idea whether he/she is better due to the fact that playing against someone changes your rating and its possible to win against someone with better rating. And furthermore your skill can improve ...

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