Marching order

The Patriots' sneaky-good offense carried them all the way to the Final Four in 2006. Travis Lindquist/Getty Images

This feature appears in the March 22 issue of ESPN The Magazine.

Why do teams win? It may seem like a silly question, especially when an extreme imbalance of talent and athleticism makes it all too obvious which team will emerge victorious. But not every matchup is so easy to figure. What makes the NCAA Tournament so compelling is it allows most favorites to triumph. Most, but not all. And picking those few underdogs is, in the end, more scientific than you realize.

We've combed through bales of stats from the past four Marches for our online Giant-Killers series -- the one in which we try to predict big upsets at the Big Dance -- and you know what? We've actually learned a thing or two. Like this: The most reliable indicators of upsets are offensive and defensive efficiency, schedule strength, turnover rate and three-point shooting. They help identify not only the Davids most likely to topple Goliaths but also bracket-busters further down the line.