I was wondering, how deep do GMs go in their opening study? Do they go this deep, or do they go even further?

How deep are main lines or book lines?

I posted this line of the KID which seems to be the main line. I found this on the shredder opening database. Is this a tabia?

Does this seem like perfect play? If so, is the fate of extremely high-level games pre-determined by the opening? =O

Take a look at any book from the GM Repertoire series. A well prepared GM is familiar with pretty much every legitimate idea that's ever been played (and recorded in a DB) in the variations they select.

Hmm, I don't think they actually memorize the entire chess database (legitmate ideas/moves), do you?

The same ideas / patterns constantly show up in slightly different forms, and of course most games are just bad so they ignore them.

Why do you care? Are you a GM? Up to at least ~2200 level over the board opening specific memorized opening knowledge isn't important (but you can never know enough common patterns in your openings).

Do you think I'm a GM?