A lot of what I've read supports the hypothesis that memory is one of the most important factors when it comes to chess mastery. Sure, there are times when calculation is important, but the majority of play seems to revolve around pattern recognition - patterns that are built up and learnt over thousands of games. This allows for fast and easy identification of the best moves in familiar positions, avoiding calculation entirely.

"From my own experience I can say that grandmasters do not do an inordinate amount of calculating. Tests (notably de Groot’s experiments) supports me in this claim. If anything, grandmasters often consider fewer alternatives; they tend not to look at as many possible moves as weaker players do. And so, perversely, chess skill often seems to reflect the ability to avoid calculations. It is, in truth, not clear that chess is a game of calculation" – Artur Yusupov