Winning the NCAA tournament requires that a team raise its level of play for six games. More specifically, a team usually needs to play better than the average level it displayed over the course of the regular season. It stands to reason that if you simply play average, even as the favorite, you put yourself at risk of losing to an opponent that plays over its head. Upsets don't happen if great teams play at their best.
Historically, there is no better example of a team playing better than its season-long stats than VCU in 2011. The Rams were ranked well outside the top 100 in adjusted defensive efficiency heading into the tournament but made it to the Final Four by playing like the team that crushed George Mason in the CAA tournament and won at Wichita State in their BracketBusters games.
With that in mind, it's instructive to look at the teams whose best is difficult for others to match. I've gone back through each team's schedule and taken its five best performances against top-100 quality competition. These performances were then adjusted for the quality of the opposition and where the game was played. Not surprisingly, many of the teams that are "scary good" at their best are also teams vying for 1-seed honors. The list contains teams like Indiana, Duke, Miami, Florida, Kansas and Michigan.
The four teams not in consideration for 1-seeds are a little more interesting. They are the teams that haven't always been spectacular, but when they've been at their best, they've played much better than their tournament seed will indicate.