I have a database (Scid) that is mostly made up of games downloaded from TWIC. I know my rating (low 2000s).
As an example, I want to play the Classical Sicilian as black. It can be reached either as 1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Nc6, or with 2...Nc6 and 5...d6, my choice.
Of course, White has many other options as well, and I want to divide my time proportionally. If I reach the Classical 50% of the time (after 1.e4), I should devote 50% of my 1.e4 black training time to it. Maybe 20% of the time 3.Bb5 is played, et cetera.
What's the best way to figure out such percentages correctly?