A puzzle about hiring, in print since Martin Gardner’s column of February 1960: candidates arrive one at a time, each must be taken or sent away for good, and you want the very best. The answer is to turn away the first 37 percent, whoever they are, then take the first person better than all of them. It finds the best one about 37 percent of the time, and nothing does better. The same number comes up a third time, and I find this one harder to look at. About 37 percent of the time the best candidate was in the group you sent away on principle, and you walk the rest of the line while nobody beats them. That is not the method failing. That is the method.