Critics contend that it is an archaic and unnecessary directive, when courtside television monitors can replay every moment from multiple directions and scorers should be astute enough to infer between a player wearing No. 8 and 53.

“In this day and age, it’s hard to believe that they’re still clinging to a rule based on fingers,” said Paul Lukas, editor of the website Uni Watch, which tracks aesthetic trends in sports. “I hate to trot out such a shopworn cliché as ‘If we can put a man on the moon,’ but it does seem to apply here.”

Adams said the reason the rule had survived was a matter of maintaining integrity and simplicity, ensuring that there was no confusion in the only sport that tracks its players by uniform number for disqualification. The N.B.A. uses the same system, but for some reason has not been hung up on the number of hands used to make the signals. (Jersey sales might have something to do with it.)

While the N.C.A.A. could explain its reason for the rule, it could not determine where and when it originated. An email from Dan Calandro, director of playing rules and officiating for the N.C.A.A., said that since 1965-66, nothing about specific numbers was listed in any of the league’s annual reports, and there was nothing on the league’s chart of significant rule changes dating to 1947.

Image The Gonzaga Bulldogs' mascot is allowed to wear No. 6. Then again, referees never have to signal his number after a foul.



Credit... Tom Pennington/Getty Images

Art Hyland, the longtime former Big East officiating coordinator and current N.C.A.A. rules secretary, said he had a feeling — but could not be sure — that the rule was in place when he played for Princeton in the early 1960s.

“To the best of my knowledge,” Hyland wrote in an email, “the numbering was a function of officiating.”