I have a classical rating of around 2000 on Lichess. I’m aware that FIDE Classical time control is much longer than Lichess classical, so I just made it as some kind of reference point.
I’m mainly working on Soviet Chess Primer, Yusupov 1, and a tactics/endgames book that I carry with me.
There seem to be three main concepts that people advise intermediate players to focus on: Tactics, calculation/endgames, and positional concepts. Many say that the first two would produce most value for time put into.
So I think my question would be that what kinds or levels of tactics and calculation skills would someone of FIDE rating 1800 have? What differentiates someone of FIDE rating 2000 from 1800?