March Madness runs on chaos that can happen anywhere, at any time and to any team. That’s exactly why filling out a bracket is an exercise in balance and overconfidence: trust the best teams, but select enough upsets to separate from the crowd. But the bracket is not equally fragile in every spot. The history of the men’s NCAA tournament offers a guide for where upsets happen, and the clearest place to start is the round of 64, where the same seed-based matchups occur each year.
