Ed Purcell was a famous Nobel laureate in physics. When Ed was not working on Physics, he was a baseball fan. He has performed a detailed study of all baseball streak and slump records. Nothing ever happened in baseball beyond the frequency predicted by coin-tossing models. The longest runs of wins or losses are as long as they should be, and occur about equally often, as they ought to. However, “treasure your acceptance,” as the old slogan goes. Purcell’s rule has simply one major exception; one sequence is so many standard deviations above the required distribution that it should never have taken positions at all: Joe DiMaggio’s 56-game hitting streak in 1941. Purcell calculated that to make it likely (probability greater than 50 percent)
