It's probably cause some of those players have not played enough games to have a established rating yet. This is sort of why I go to someone's account and see if they have played over 40 games to determine if their rating is established yet.
Confusion about chess rating system
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I've done the same. I look at what their highest rating is that they've achieved and no way are they playing at that level. I look at the date it was conceived and it's like they seemed to have earned it the week their account was created but then they got cut down to size.
That's how the Glicko rating system works. Very large swings in the beginning as it quickly estimates your rating. The more games, less swing, more accurate. Took the liberty of "search forum" for Glicko RD (rating deviation). Lots of threads:
http://www.chess.com/forum/search?keyword=Glicko+RD
amilton542 wrote:
I've done the same. I look at what their highest rating is that they've achieved and no way are they playing at that level. I look at the date it was conceived and it's like they seemed to have earned it the week their account was created but then they got cut down to size.
YEs, this is correct.
For about the first 20 games, your rating can swing greatly as it attempts to adjust to your strength.
It took me more than 6 months to get to get back to my highest rating.
baddogno wrote:
That's how the Glicko rating system works. Very large swings in the beginning as it quickly estimates your rating. The more games, less swing, more accurate. Took the liberty of "search forum" for Glicko RD (rating deviation). Lots of threads:
Chess.com should hire you as a goodwill embassador for new users. 
I want to know about the rating of draw.
rezwansaki2012 wrote:
I want to know about the rating of draw.
It works the same as ratings for wins. Except you don't get/lose as many of the possible points.
Jun 25, 2015
0
#9
Also a good referrence:
https://support.chess.com/customer/portal/articles/1444777-how-do-ratings-work-
There is a link there to an article on the site that goes into a bunch more detail.
Jun 25, 2015
0
#10
leuk dat rating systeem maar als je internet modem kapot gaat ben je wel erg lang bezig dat in te halen.reden waarom ik minder 1 dag per zet speel
I'm a bit confused how the chess rating system works here.
On average if I win or lose a game it works out at about several points or so. However, some opponents I play if I win or lose their rating just sky rockets to some ridiculous value plus or minus, how does that work out?