Ratings are broken, workaround explained

The Rankings have been broken for months.  I've reported it to Support multiple times, months ago, but never got a meaningful response.  I wouldn't ever expect it to be fixed.  If you're wondering why your rank or percentile looks screwy or is missing completely, there's your reason.  That said, I can help you understand some of the quirks, and offer a rough workaround.

(1) Rank and percentile don't change as you play.  These are updated only once a day, which seems to be some time between 3:00am and 5:00am Central Time.  That's documented exactly nowhere.  If they're not gonna update it live they could at least say so, but they don't.

(2) Rank and percentile are not reported.  Maybe your rank and percentile aren't listed at all for some categories.  For example, my own Blitz rank and percentile have been listed as "N/A" for months now.  (Reported to Support multiple times, months ago, no meaningful answer.)  If that's the case for you, don't expect it to get fixed any time soon, but do rest assured that you're not the only one affected.  Further below I'll show you how to approximate your percentile yourself.

(3) Percentile figures seem off.  If you're expecting that your reported percentile should match what you get by dividing your rank into the number of players, it won't, for at least two different reasons:

- (a) First, Chess.com might be using a different figure for total number of players when they figure your rank  vs. when they figure your percentile.  Check out the Global ratings chart for Rapid.  It says there are nearly a million players, but if you add up the number of players at every level in the chart, there are only about half that many players.  Some have suggested that Chess.com uses all registered players for the total number of players, but only active players when figuring rank.  Who knows?

- (b) Almost all players share the same rating with lots of other players.  There are 381,000 Rapid players sharing the 701 distinct rating levels between 900 and 1600, which would be 543 players at each rating level if they were distributed evenly.  Imagine a system where each person has a rating between 1 and 10, and there are 1000 people at each level:

1000 @ 10
1000 @  9
1000 @  8
1000 @  7
1000 @  6
1000 @  5
1000 @  4
1000 @  3
1000 @  2
1000 @  1

Now, imagine your rating is 7.  What's your rank?  Are you #3001 or #4000?  Because everybody between 3001 and 4000 has the same rank, so how your rank is reported between 3001 and 4000 is kind of arbitrary.  Your percentile rank (the number of people with scores equal to or lower than yours) is 70.  If your rank was reported as 3001, then you'll get a pretty good estimate of percentile by dividing your rank into the number of players (1 - 3001/10,000).  But if your rank was reported as 4000, then your division will show your percentile as 60 (1 - 4000/10,000).

(4) How to actually figure your rank and percentile.  You can use the Global charts to approximate your percentile.  When you point to the chart with a mouse on the web-based version, you can see the number of players at each rating level.  First, add up the number of players.  (For Rapid, it's about 512,000 -- I did that one for you.)  Then add up the number of players above or below you.  You'll have to round your rating to the nearest 100 (or sometimes the nearest 50) because that's as fine as the chart gives the numbers, but it's better than nothing.  For example, with my rating of 1600, I see there are about 65,338 players above me, so about 512,000 - 65,338 = 446,662 below, so my percentile is around 87.2%.  That's pretty close to the 91.4% that's reported.

Below are the rating distributions for Bullet, which can help you figure your percentile for that.

Now, would someone like to be helpful and post similar tables for Blitz, Rapid, and Daily?

Since percentile stats are updated nightly, I assume these figures are updated nightly, too.

Yes, as Chess.com gains lots of members (or loses lots of members) the numbers in the table will be less useful, but the method to calculate as I listed above remains the same.

Is it? A lot of new people join every day, but I don't think nearly as many people close their accounts. It's just that they stop playing and become inactive.

 I can't wait until I have my 30 days so I can join the Cheaters Forum. Must be very enlightening, as if I need more enlightenment.

Looks like you meant to say rankings are broken, not ratings are broken.

 Yes, I did mean to say that Rankings are broken, not Ratings.  Unfortunately I don't see a way to edit the title of the thread.