Adam,
- Chess.com ratings are calculated slightly differently than USCF ratings are.
- Chess.com has a different population than USCF has.
- Chess.com's "online rating" is based on correspondence chess, which is a different time control than USCF's. There is no time control that matches USCF's time controls.
Any comparison between the two ratings can only be done on a very general basis, knowing that some players will have ratings vastly different from others.
Ratings here are not deflated. They measure the population that plays.
So, I've read all the posts saying that you can't compare chess.com and uscf ratings, but that's obviously nonsense. If a person has two ratings, you most certainly can compare them. If a group of people have ratings, you can discuss them as a group.
I've also read all the posts that say that chess.com ratings are inflated... uh, no.
I've checked about about twenty people I know, who actively play USCF tournaments and chess.com blitz, with ratings ranging from 1200 (uscf) to 2300 (uscf). In -every- case, their blitz rating is about 2-300 points lower on chess.com when compared with their uscf standard rating. I think this is a pretty consistent pattern.
Does this mean that someone with a chess.com blitz rating of 1500 is as good as a uscf 17-1800? no. long multi-hour games require a degree of discipline and concentration which most blitz players won't have. however, i think it is fairly clear that an 1800 uscf will normally be about 15-1600 on chess.com blitz.
Should we be surprised that chess.com ratings are deflated? No, we already know from FIDE that the international pool of players is stronger than the American average. [Mod Edit: Please refrain from making offensive comments about Nationality.] That probably accounts for about 100-150 points. The rest is probably caused by the turbulent nature of blitz and differences in how chess.com calculates ratings.
-Adam Rinkleff