Does Tactics Trainer always give you a problem ID that you have not done before, until you have done all the problems? Because right now I'm getting literally exclusively 2100 puzzles even though my current TT rating is a solid 100 points above that range; I think it may because the 2200 puzzles that I have not attempted have run out (which is natural considering I've done over 5000). Not complaining or anything, just want to confirm if this is how it works.

Do you mind if i ask what your rating is, mine is 1050, i,ve never been above 1120, i,ve done 3000 puzzles

Doesn't seem to have much relevance to the question, though I implied that my rating was currently in the 2200s.

If you want to know how it works, i think you,ll have to ask the staff.

I thought the staff is supposed to respond here.

No. I've seen several problems more than once.

Oh yeah, I've seen dozens and dozens of duplicates; but I mean the exact same ID: with the same comments, tags, everything. There was one time and one time only where I think I saw the exact same problem that I had come across in rated mode, but a couple reasons I'm starting to doubt it:

1) It has only happened once (to my best knowledge, of course); you'd think it would happen more than that after solving thousands of these;

2) If they just repeated, I would not get literally 50+ problems in the 2100-2150 range in a row, when for that whole time period my rating was in the ~ 2220-2270 range.

In fact, at this point I'm at ~ 2300, and indeed, now I'm starting to get 2300-2450 problems (Although I have not seen a 2200 puzzle in a month ). But it's strange that when my rating increased just a tad that I immediately went from seeing problems in the low 2100s with extreme consistency to problems in the 2400s.

I believe that I've seen the same comments on repeated problems, but have not carefully attended to the IDs. Perhaps they differ. It would be nice to have an administrator weigh in.

Ok: I can confirm nearly for sure that problems do repeat now. I saw a puzzle with one of my comments from a few months ago, and I was doing it in rated mode at that time.

Thanks.

I'm pretty sure you shouldn't see any duplicate problems (while in rated mode).  You can see duplicates in un-rated mode.

It doesn't happen often in rated mode, but it definitely happens.

I have solved around 5000 problems. And it happens nearly every training session now.

Effective training calls for repetition. Chess.com defies logic in their denial that such is built into TT. One should hope for an occasional duplicate.

I've been getting duplicates too....and see the same comments on the problems xD.

not entirely sure if because of lack of problems or chess.com does it on purpose....I guess repeating the same problems every so often can be beneficial.tactics are all about burning more and more patterns into your skull.