Author Terence Reese wrote that the difference between amateurs and professional was that the former could "see" (locate) only 26 cards, while professionals could "see" 52 before the hand was over. Another commentator on this site once remarked that this could occur by the sixth or seventh round (out of 13).
Suppose you're declarer. An opening lead comes from West, and dummy goes down. Now you can actually see 27 cards. More to the point, West probably led from a suit in which he and partner hold 8 or 9 cards, meaning that they are likely distributed 5-3 if eight cards, and 6-3 or 5-4 if nine cards. By the rule of sequences or the rule of 11, you can probably guess WHICH five cards west holds, especially after East plays. So you can now "see" 34-35 by the time the cards reach your hand. If West led his partner's (bid) suit, that factors into the equation.
What happens next? That is, how do you bring your knowledge of 34-35 cards up to 52, and in (roughly) how many rounds. It might be fairly easy if one or both opponents bid. But what if they haven't?