That is the strategy of opening preparation. For the most common openings, GMs often have a 20 move sequence memorized. The time limit of chess matters a lot, s

That is the strategy of opening preparation. For the most common openings, GMs often have a 20 move sequence memorized. The time limit of chess matters a lot, so the strategy is to break your opponent out of their preparation with a move that is unintuitive or considered untenable, after you have determined the ways in which it is actually better than widely considered. The ideal at top level is to get to move 20 or so with a slightly better position, essentially all of your time (because you've been playing memorized moves), and your opponent already having used most of their time.