Summary: When data arise from a situation that can be modeled as a collection of \(n\) independent Bernoulli trials with success probability \(p\), a simple rule of thumb predicts the approximate length that the longest run of successes will have, often with remarkable accuracy. The distribution of this longest run is well approximated by an extreme value distribution. In some cases we can practically guarantee the length that the longest run will have. Applications to coin and die tossing, roulette, state lotteries and the digits of \(\pi \) are given.