I don't know... for me the way this tactical training is working and calculates rating is very mysterious...
I started working on it several months back, and it looked like 1800s to 1900s were my place and it was hard to get out from it.
Now mind you, I'm familiar with chess tactics, and have been for a long long time...
Then suddenly one day I break 2000. So I think - well fine, so I'm an 2000 trainee. Wonder if I could make 2100 one day?
Working and working, three problems a day, and suddenly I hit it! Then drop back to 2000s again, resurface on 2100, well fine, a nice respectable level, who can ask for more?
But then strange things started to happen, as ever couple of weeks or so I would strangely break into another new level, each one hitting me as a complete surprise - in rapid succession there came 2200, 2300, 2400 and the last one was just 2500. Couldn't really figure out if it was me getting better, or a freak in the system...
like that in many problems you get really a lot of time to calculate, or that in many cases even if you miss the idea you still get partial credit for guessing your way around, or I don't know what... problems higher rated not really being more difficult than problems 400 or 500 points lower...
It got into a state where almost every time I play TT I break my record once or twice, or several times over (last time I played I broke it six times to make that crazy 2500 number)
Go figure...
In TT.
So, I creep up to mid to high 1900's, (even hit 2001 once)
Then I get a bunch of problems way over my head, and fall back to 1750. This is happening time after time, have I reached my max?