The Secretary Problem

The rule was made famous by the secretary problem of the 1960s. You interview candidates one at a time and must accept or reject each on the spot — no callbacks. How do you give yourself the best shot at hiring the very best one?

The answer: reject the first chunk no matter how strong they seem, then hire the first person who tops everyone before them. The best chunk size turns out to be 37%, and it beats random hiring by a wide margin.