Sure, playing chess needs intelligence, dedication, and good chess players are smarter than an average person. But it’s waaaay exaggerated in movies. I’m a math researcher, and in any movie, my department will be full of chess geniuses. But in reality, only about 10% of them even play chess.
I think DeGroots work in the 30s and 40s shows otherwise. Grandmasters know rather quickly what they were going to do in general as they orient to the board state. Then they explore a small set of moves and explode them into a few moves into the future and pick the best candidate. Finally, they spend time verifying their selection.
They have good memories, for sure, but for real game states. This is a quote from Herb Simon, an important early researcher in psychology and computer science:
That makes sense. Here’s a video of Magnus Carlson identifying famous chess positions without seeing that actual pieces in the board and usually knowing what happens next. It’s incredible
https://youtu.be/J5BnJvhSryc
Apparently Carlson loses his keys regularly as well. So this type of memory is domain specific.