Please don't bump this thread.
chess.com ratings are deflated against USCF
I have found the same results as Adam at my local chess club, our blitz ratings on chess.com are about 300 points behind our actual over the board rating

I would absolutely LOVE to have a USCF rating of myBlitz + 200..
Is it so that the higher you go the less differences in ratingnumbers? In Norway there are ca 100-300 points difference between local rating and fide at 1400, but at 2000 the difference is close to zero.
Kind of a funny thing that a topic such as this causes so much debate.
I would suppose most people can see the merits to both sides of the coin.
Chess is chess, so on one hand no one would expect a GM to have a rating of 1400 chess com blitz. At the same time playing games online is a different (with overlap) pool with different effort level put forth then OTB.
There are a lot of factors at play and as people have stated a number is a number. What blitz rating you have online is a measure of what you results you have had against others online. What rating you have OTB is what results you have against others OTB.
Why people get so mad about trying to compare the two numbers is confusing to me.
It is obvious that there is some sort of correlation between the two numbers even though they may be unrelated in what they meaure. what exactly the ratio is would be very hard to say, The reason for the correlation is that both numbers attempt to gauge ability at chess.
Clearly there will be outliers I.e. 2400's that are better blitz players then GM's But that does not mean that there is no meanful way to interpet the data at all. In fact I think the hardest thing about making meaning is getting the correct data in the first place.

Yeah it's pretty much been conclusively proven now.
There is a lot of supporting evidence, but in no way has it been "conclusively proven."

Actually FIDE ratings are higher than USCF.
1600 FIDE = around 1500 USCF
From http://glicko.net/ratings/rating.system.pdf.
USCF =
180 + 0.94 x FIDE if FIDE <= 2000
20 + 1.02 x FIDE if FIDE > 2000
you should think about the USCF rating being inflated, not the chess.com rating...
Yeah this is true, brah.