Do you think there is a correlation between a player's 'Tactics Trainer' rating and Online Chess rating?

If yes, to what extent...

-500

 what was that supposed to mean...

My 'Tactis Trainer' rating is 500 less than my 'Online Chess' rating.

Is the training helping you in improving your rating?

It is fun, for sure...

Is it helping you in noticing patterns while playing real time?

Yes, because TT always posts 5 of the same sort puzzles. When you start to think "aargh, it´s again Boden mate including queen sac", then you can be sure you will recognize the pattern in a real game as well. 

It is great if you can recognize...

However what is more beneficial and difficult is the ability to arrive at those positions...

are you to recreate those positions in your games?

=) Well that is the problem, you should be able to recognize patterns not positions after X moves. Except opening traps of course, always try to look if there´s a hidden tactic, perhaps spread over more moves. Always look for same pieces, (half-)open diagonals etc. Just play a lot (like I do), not too many games at a time, and eventually, also in OTB you will see the patterns!

 Interesting, that makes a lot of sense...

 that's strange....my tactics, at 1700+, is way higher than my online chess.

 Any explanations?

Maybe you have not played enough games...

Or you´re very good at tactics. Mine (TT) was some time 2300, while online was less that 1800...

 TT rating of over 2300 means at that point in time you were in the top 99 percentile, and at the same time if you game rating is in the 1800 range, safe to assume around the 96 percentile mark, it is safe to you were not giving you all while playing your games...

Perhaps, I´d rather say that the game doesn´t exist of only tactical (puzzles / sacrifices). I wish it would be true! But after you´ve done some tactical state-of-the-art moves, if you´re positional rubbish, you´ll never make it to a win...

Maybe... Maybe not.

You can be good at tactics by studying combinations. After a couple of times, your tactics rating will increase surely.

But if you are not good at openings, only by a wrong move on opening, you're going to lose the game. Because you'll not be able to reach that position to use your combinational skills.

If you start by 1.e4 and your rival answers by Sicilian, you have to know the variations. You should have been studied it. If you didn't, it doesn't matter if your tactics rating is 2200... You'll lose against someonewho is 1700 :)

Knowledge is power, I agree with you on that front but knowledge alone will not win you games, you need to understand how to better exploit any situation that you find yourself in and that is where tactics come in to picture...

My highest TT raing is 2300, and at that point of time, my OTB performance was also very strong...

But it is a huge advantage if one can spot weak squares and unexpected forks...

Obviously there is some correlation. The better you are at chess, the higher both ratings will be. The higher one rating is, the higher the other rating will be, provided that you actually take the time to play both. Obviously some Masters and other high-rated players will have low Tactics Trainer ratings simply because they don't bother with it. But if you forced everyone to play, the better you are at chess, the higher all of your ratings will be.

But as to a direct correlation, I doubt one will ever exist. The Tactics Trainer rating is not a real rating; it is simply a number that the program uses to feed you problems of an appropriate difficulty level. A 1600 score on Tactics Trainer doesn't mean that you were able to beat a bunch of players with an Online Chess rating of 1400s and 1500s and 1600s. It just means that you solved a problem that others with lower scores were not able to solve on a consistent basis.