[quote="reflectionofpower"]
I am going to assume Lyudmil was saying not to be so structured in missing the essense of going beyond the norm,finding new ideas,exploring yourself?
[/quote]
maybe, but if you do that while playing a game it costs you lots of time.
So, besides, knowing strong lines, a good preparation and opening knowledge of the 'best' lines can save a player quite some -imporant - time in the opening stage; which then can be utilized during the middle/endgame, and when they have chosen a line -depending on Blacks play- which gives them a better game with White, then winning is ofcourse much easier then when you start of with a simple 'equal' line as eg the Berlin.
Some may argue that this ie memorizing current advanced (computer assisited) opening theory- is not possible because of the huge tree of possible opening variations. Which is only true up to a certain point, my current 'top' book which i use (with interface ChessPartnr) on ICC is only about 23 Mb. When the engine can handle the position itself, there's not much need to store it in the book.
So when looking at the book variations, a player can get a reasonable good idea about which lines to play without needing excessive stuyding time or a photographic memory. Ofcourse you need some motivation to do so, just as studying eg endgame theory, and the player needs a reasonably good memory, but we know of Magnus C that he has an excellent memory, so this can't be the bottleneck. Maybe it's just a matter of motivation, but certainly a player as eg -besides those i already mentioned- Caruana might have such desires.
Unfortunately however, for them, my opening book is not for sale. But if they wait a few years, they can see my correspondence games also in the large Chessbase database

NB i did think of writing a new book with a super-GM repertoire, but now it seems that Black always can equalize completely(*), i cannot determine a best first move for White, c4, Nf3, d4, g3, and e4 they all are good. So
my enthusiasm for such a project has been decreased. Maybe just an article about solving chess (a draw with best play) with some examples would do.
jef
(*) occasionally, only when looking much deeper, i still manage to find a little improvement, eg against the Slav, but then again later Black can nullify it again. An endless process, for sure. Also with the Catalan, contrary to what Avrukh was suggesting in his books, i do not think W can maintain advantage against Black best play. Also sometimes, when an engine eval is changing, some 'best' lines are changing a little, but then again Black can equalize.
PS if i write having analyzed openings up till 'perfection', i mean
up till drawing point; so to be more realistic, it's *almost* up till perfection, ofcourse it also depends on the engine eval, which is not always perfect (although i also often used Komodo8), ie subject to possible adjustments in future, but i'm ahead of current 'theory' eg in the Najdorf.
Last important point is that not only the objective of maintaning a slight positional advantage for White is important, depending on the opponent a GM also should be able (and often is) to choose a sharper line when mastering such a variation, sometimes even at the expense of a little positional advantage; which i wrote sometime ago that a good book should not only have parameters as statistics, or -as in Aquarium- end(minimaxed)eval
but ídeally also 'sharpness, eg such as the indicator in Fritz14. An idea for the developers of Aquarium maybe (example, against e4 imho both e6 and c5 are equalizing, but obviously most Sicilian variations are more double edged)