I found this article by Sally Rooney at the New York Review (archive) fascinating:
The last remaining red ball is stranded up by the cushion on the right-hand side, and the cue ball rolls to a halt just left of the middle right-hand pocket. The angle is tight, awkward, both white and red lined up inches away from the cushion. O’Sullivan surveys the position, nonchalantly switches hands, and pots the red ball left-handed. The cue ball hits the top cushion, rolls back down over the table, and comes to a stop, as if on command, to line up the next shot on the black. O’Sullivan could scarcely have chosen a better spot if he had picked the cue ball up in his hand and put it there. The crowd erupts: elation mingled with disbelief. At the end of the frame, when only the black remains on the table, he switches hands again, seemingly just for fun, and makes the final shot with his left. The black drops down into the pocket, completing what is known in snooker as a maximum break: the feat of potting every ball on the table in perfect order to attain the highest possible total of 147 points.
Watch a little of this sort of thing and it’s hugely entertaining. Watch a lot and you might start to ask yourself strange questions. For instance: In that particular frame, after potting that last red, how did O’Sullivan know that the cue ball would come back down the table that way and land precisely where he wanted it? Of course it was only obeying the laws of physics. But if you wanted to calculate the trajectory of a cue ball coming off an object ball and then a cushion using Newtonian physics, you’d need an accurate measurement of every variable, some pretty complex differential equations, and a lot of calculating time. O’Sullivan lines up that shot and plays it in the space of about six seconds. A lucky guess? It would be lucky to make a guess like that once in a lifetime. He’s been doing this sort of thing for thirty years.
What then? If he’s not calculating, and he’s not guessing, what is Ronnie O’Sullivan doing? Why does the question seem so strange? And why doesn’t anybody know the answer?
And, after reading the article, watch the match described. I’ve been playing pool since I was a teenager; I’m decent at best. This makes me never want to pick up a pool cue again.