Unknowable. You really can't compare the two since they are for different time controls, they use a different rating system, and they have a different player pool.
What gives you the most accurate playing strength?

Unknowable. You really can't compare the two since they are for different time controls, they use a different rating system, and they have a different player pool.
Maybe it is knowable?
Do you have an OTB rating? What is your OTB rating closest to, or always the same number higher or lower than on an internet chess site, i.e., ICC, Chess.com, Chess Cube?
Example: My Standard Live Chess rating is always 200 points higher than my USCF OTB rating.
If most people find that to be the case, then I could have a good approximation of my USCF rating, i.e., my Live Chess Standard rating at a time control of 15 10 = 972, therefore, my USCF OTB rating would be 772. That sounds pretty low!
At my club tournaments, we play 60 0 games, so maybe I should try even longer time controls on the internet to get a better idea of my true playing strength.
I can't play in tournaments right now, because my low back can't tolerate long periods of sitting, or standing. So, that is one reason why I am curious about interent ratings as they relate to club ratings, since it will be a long time until I can sit and play at my local club.
Considering different pools of players, internet chess pools are much larger than chess club pools, I would guess. On the internet, I am confronted with a huge number of playing styles and openings, unlike my experience with my small chess club in California with a pool of about 16 players. The internet presents a greater challenge for me at the moment, and there are 1000's of players at my internet rating here, Chess Cube, and the ICC.
Perhaps playing on the internet would make one a stronger chess player than playing with the same 16 guys over and over again.
It depends on a lot of things--time control, mouse slips, ability to play 2D. My rating is considerably lower on this site than in real life, because I have a hard time thinking in 2D, I mouse-slip alot, and I play exponentially worse as my time control decreases. However, the quality of game I get from a 1200 varies a lot in comparison to the quality of game I get from someone rated 1200 USCF. It really just depends on how much the computor variables affect you in proportion to the rest of the chess world.

paulgottlieb wrote:
Why not just play some USCF rated OTB tournaments? There's fun, exciting, and not too expensive. And you will certainly get a precide reading on your USCF rating
I wish I could. As I mentioned in my IPad topic, I can't sit for more than a few minutes with a bad low back. It's not a life or death thing, knowing what my OTB strength might be. Just a curiosity.
What I have learned from the posts thus far, is that if there is a difference between Internet and OTB rating, it's not that much...maybe a class difference at most, I.e. Between Class C and Class B.
What internet tactics trainer, or internet chess format would give me the best approximation of a USCF rating.
Example: My 15 10 Live Chess Standard rating is currently 972. What would my USCF rating be, approximately? Thank you.