Some time ago I returned back to Chess Tactics Server after years of absence. So far I've done a few thousand problems, and am getting back into the groove of things. At first it felt a little weird after the ICC problem set, but I guess it went surprisingly well considering the length of the break.
When I left CTS in 2008, I was at 1632 with a 80.0% total accuracy over 107832 problems. Now I'm at 1615 with a 80.4% total accuracy over 114406 problems. which leaves me with 857 wrong for the last 6574 problems, and a 87.0% accuracy over that time. Can't really remember what kind of session averages I used to do before, but 87% doesn't really sound all that great. I'd like to get that past the 90% mark at the very least.
What's interesting though, is that the thousands of blitz games I've played during the break, don't seem to have any significant effect on my CTS rating. Yet my 5-minute blitz (peak) rating has risen from 1431 to 1705 over the same period. You might think playing a lot of blitz would improve tactics as well, but that doesn't seem to be the case. Just like the inverse wasn't true back when I began blitzing, when my 1550 CTS (or 1800 RHP) didn't affect my blitz almost at all. Instead I started from 1100-1200 and slowly fought my way up just like everyone else.
All of which is in line with my earlier hypothesis, that contrary to a popular belief, blitz is not so much about tactics. Or at least tactics don't dominate blitz strength in the way it's usually portrayed to do. Instead, blitz seems to be mostly about experience and familiarity with your openings and typical positions.
Why study tactics at all then? Well, even though it doesn't seem to do work that well for blitz, it did have a huge positive effect on my slow chess. And I firmly believe that anything you understand about slow chess, you can eventually internalize and transfer to blitz, through experience. Repetition.
CTS: 1615, 114406 problems, 80.4%