ICC Help: provisional
This help file contains some information and restrictions regarding provisional ratings. Please read help ratings for a complete description of the ICC rating system.
You have a provisional rating if you have played less than 20 rated games in that rating category (bullet, blitz, standard, wild, bughouse, or losers).
When a provisonally-rated player plays a player with an established rating, the established rating doesn't change very much. This is why you sometimes only gain a point or two for winning a game even against a higher-rated player (because that player hasn't played many rated games in that category yet).
There are restrictions on who you can play during your provisional rating period:
(1) For a given rating category (e.g. blitz), you can't play more than four of your first twenty rated games against the same opponent.
(2) Until you have established your rating, you can only play players within 300 points of your rating. There are some exceptions: if your rating is below 1200 you can play anyone up to 1500, and even if your rating is above 2100 you can play anyone above 1800. Also, this rule doesn't affect unrated games, resumption of adjourned games, bughouse games, or tournament games. Your "seeking" ad will automatically reflect the rating range restriction.
We have a way around both rules for tournaments and special events, via TDs such as Tomato.
The reason for the rating-range rule is not only to help prevent some types of rating abuse (see help abuse and help agreement, which are by no means obviated by the new rule), but to help make sure that each game result during a player's provisional period provides the server with useful rating data. The hope is that all ICC ratings will become more accurate over time, and that the new rule won't get in the way of your finding opponents and enjoying the club.