Walker, from his 1982 book, The Sinister First Baseman and Other Observations:
In baseball, some numbers are known, some are not, and the meaning of most of them can be debated. But there's one number everyone knows and agrees with: three. Three outs and you're gone. Period. The end. All runners cancelled, all theories moot, all probabilities zero. That number must, in any rational evaluation of the game, dominate planning.And from Part 2, linked above:
Despite all the seasons that have flowed by since [Branch] Rickey and [Earnshaw] Cook and [Bill] James, there remains to this hour a great divide, a sort of cultural barrier, between "old-time baseball men" and the so-called "new breed" of analysis users. That pains me, because though the details of analysis can be abstruse and mathematical, the basic concepts, with only a modicum of patience, can be explained even to hostile disbelievers, who disbelieve for the very reason that no one has ever troubled to make those clear explanations to them — at least not in language they speak.