Earlier quoted context omitted.
> Below 1700 or so, openings are mostly a waste of time Here is a counter argument - below 1700, someone who knows the strength of an opening would outperform those who do not.
I disagree. If there are two 1700 players, the opening player is only better if the game goes according to the prepared moves. A good tactical player who realizes you are going via prep will make a stupid move and pull you out of book. From this point on the tactical player has the advantage because he has experience defending random stuff, while the opening player has to figure out why the move so stupid it isn't ev…
That only works against a badly prepared player. Learning an opening isn't just about memorising moves, it is also about understanding why the moves -- both your own and your opponent's -- are good. If you have studied an opening well, you will understand why a stupid move is stupid and be able to punish it. Of course you may still end up messing things up and lose the game later on, but you should be able to emerge from the opening with an advantage.