How "mad" was the first weekend of the NCAA tournament?

Who is the new NCAA tournament favorite? (0:56)

The No. 1 overall seed is out. The preseason No. 1 team is out. Some other top teams have been in nail-biters. With 16 teams remaining in the NCAA tournament, we need a new front-runner. (0:56)

The First Round of the NCAA tournament was surprisingly normal. Then the second round happened. Looking back at the first weekend, there were surprisingly few upsets, and even those upsets were not that surprising when looking through the lens of ESPN’s Basketball Power Index (BPI).

For the first time since 2007, the top-four seeds went 16-0 in the first round, and thus the first round seemed sane for a tournament often referred to as “Madness.” The higher seeds starting 16-0 is not very likely; BPI projected a 36 percent chance of that this year.

The upsets that did happen were not surprising. Of the five double-digit seeds most likely to win their first games, only Marquette failed to do so. BPI gave a 62 percent chance that at least one of these schools would make the Sweet 16, and Xavier was the only one to do so.

The Madness really set in over the weekend, as Duke, the Vegas favorite, and Villanova, the third-most likely team to win the tournament in BPI Projections, lost in the Round of 32. According to the BPI projections on Selection Sunday, there was only a 4 percent chance that neither Duke nor Villanova would advance to Sweet 16. Additionally, the ACC, which was the most represented conference in the top 50 of BPI, was able to get only one of its nine teams to the second weekend. There was only a 1.5 percent chance of one or zero ACC teams making the Sweet 16, according to BPI.

The main benefactor of this madness is Florida. The Gators' chances to get to the Final Four rose from 11 percent going into the tournament to 47 percent, which makes them the favorite to get out of the East Region. Their chances to win the title also rose from 2 percent to 12 percent, which means the Gators are the third-most likely champion of the remaining 16 teams.

Since 2008, every national champion except Connecticut in 2011 and 2014 has been a top-three team in BPI. Going forward, that leaves Gonzaga (No. 2 in BPI on Selection Sunday) and UNC (No. 3 in BPI on Selection Sunday) as the favorites, with 19 and 16 percent chances, respectively, to win it all. Each team increased its title chances by winning and seeing heavyweights Duke and Villanova lose.

Although No. 1 seeds are still the most likely to bring home the title, No. 4 seeds, including Florida, are the second-most likely seed group to win it all. All four No. 4 seeds are still alive -- the only seed to have all four teams make the Sweet 16.

Looking forward to the Sweet 16, there are three games between top-16 BPI teams: Purdue (13th) vs. Kansas (8th), West Virginia (5th) vs. Gonzaga (3rd) and UCLA (11th) vs. Kentucky (12th). Gonzaga is the only team in these matchups with a greater than 60 percent chance to win. The biggest favorite in the Sweet 16 is North Carolina, which is a 7.6-point favorite (76 percent) to advance to the Elite 8, according to BPI.

For up-to-date BPI projections and changing NCAA Tournament chances to advance, visit ESPN.com/BPI and ESPN.com/Analytics.