About the "percentile" in stats.

Just curious about the "percentile" in stats (the percentage of players whose rating is lower than yours).

How does it work? Is it the percentage of active players or everybody who ever registered?  Because it dropped suddenly while my rating was going up. So have they removed some inactive accounts or maybe it does not work correctly?

And it's not a big deal I'm just curious.

There are a few other posts like yours. I haven't seen anything posted by Chess.com that actually explains it. It seems reasonable to speculate that they have been changing the definition of what they are using as "active players".

Your current 1745 rating results in a 98.7 percentile.

I was able to find another post from last March that actually took the time to write down the percentile calculations for the 99th percentile.

www.chess.com/forum/view/community/whats-the-rapid-rating-to-be-in-99-9-

percentile

It looks like your 1745 would have been 99.2 percentile in March 2023 while it is only 98.7% now.

Basic math says that you were ranked against 6,065,230 players.

That contrast with the leaderboard, which currently reports 68,923,755 rapid players.

It looks like there is a slipped decimal place somewhere.

To me, a ranking against about 6 million active rapid players makes a lot of sense. I don't believe that there are 69 million active rapid players.

Thank you for your answer. I apparently misspelled my search so I didn't find any topics. It would be interesting if chess.com what they have changed.

There's been some ongoing back-end work on the data the leaderboards and percentile data is based on. So there will be changes as that work progresses.

This thread should be in the Hot topics, since the Glicko system is confusing a lot of people. They are schooled in the old system, when an average player was around 1500 ELO - that's not the case anymore.

An average player is around the 50th Percentile, regardless of which rating system is followed.

One thing that you will encounter is that players with the same rating will have different rankings. Thus, your percentile will depend on the number of people with your rating and whether your name is at the head or tail of the list.

That's why the overall Percentile in a reference group is so much more telling, than just a simple ELO calculation. I looked at your stats which places you at the 95th Percentile in Rapid - meaning that 95% of the members on chess.com have a lower Rapid rating than you.

Here: https://www.chess.com/stats/live/rapid/woton

If you don't have a Percentile ranking, you need to play more games. Also, you need to play them often in order to get a proper Percentile ranking. It's the Glicko 2 system.

I honestly have the same thing that I don’t understand. I am a 1366 rapid player. With a 91.1% percentile while I found someone who is 1364 Rapid who is in the 93.9% percentile.

As the amount of members increases, the Percentile value will diff a little. Nothing strange with that.

I honestly thought that as your rating increases, the percentile goes up. But apparently now I know that many factors are needed to be plugged into the percentile. Hence why some people get confused by this. Thank you Ritterschildt : )

The thing needed to understand is that The Percentile is NOT the same as The Percentage. It is more like a reversed percentage, and in this case it has to do with the group or pool of players.

I'm pretty sure the percentile value isn't calculated real time but the rating shown is going to be close to the most recent one I think. The rating when the percentile was calculated may have been different than current, so you can see some differences there.