Apr 9, 2021 Welcome to The Opener, where every weekday morning you’ll get a fresh, topical column to start your day from one of SI.com’s MLB writers. A clinical psychologist in London devised a trial in 1960 in which subjects were told a series of three numbers, 2-4-6. The subjects were then instructed to figure out the “rule” behind the sequence by offering other series of three numbers, to which the psychologist would say if the proposed sequences fit the original “rule” or not. The psychologist, Peter Cathcart Wason, found that people kept proposing sequences that fit their perception of what they thought the rule to be, such as only even numbers or numbers that increased by two.