What Are The Odds: 1-1-1-1

Obviously, all four #1 seeds reaching the Final Four is a rare occurrence, as this is the first time it's happened. But thinking about it abstractly, it doesn't seem all that unlikely, especially in a year that the top seeds were clearly the best teams. No single unusual thing happened, but 16 likely events combined to form one very unique one.

Prior to the tournament, Basketball Prospectus' Ken Pomeroy placed the odds of a 1-1-1-1 Final Four at 3.5%. That was probably a good estimate at the time, but the way things played out, it ended up being higher. Two teams had unusually easy paths to San Antonio:


Kansas' path has to be one of the easiest ever, although they're paying for that with their opponent on Saturday (UNC is favored by 3). Instead of playing Clemson and Georgetown/Wisconsin, they faced Villanova and Davidson. It could be argued that the Wildcats were better than the Badgers- after all, they did beat them- but there's no question that KU would've been favored by fewer than 9.5 against Wisconsin. With these four opponents, the oddsmakers gave the Jayhawks a 62.0% chance of reaching San Antonio.

From the start, UCLA had the benefit of a weak bracket. The craziness in Tampa on the first Friday of the tournament made it even worse; Western Kentucky was certainly not one of the 16 best teams in the country this year. In the regional final they drew Xavier, a good team but certainly on the level of Louisville, Texas, or some of the other 2/3 seeds in. Their performances in rounds 2 and 3 didn't inspire too much confidence, so despite the easy draw, the Bruins had only a 53.2% chance of winning the region.

The other two teams had more traditional paths:

Memphis really had to work to get this far. KU was favored by 9.5 this afternoon against Davidson, which was their closest spread- Memphis was a 9.5 favorite against Mississippi St. two rounds ago, and it only got tougher from there. This is partially because people were down on them- well, mostly just their foul shooting- but also a function of playing tough teams. Unlike the West and Midwest, there were no big upsets in the South. Memphis is the most unlikely Final Four participant, with a 31.5% chance of getting here.

Carolina didn't play bad teams, but were significant favorites in each game simply because they're really good. If Memphis had played Louisville this weekend, the Tigers would've barely been favored (if at all), certainly nothing close to the 5.5 point line in last night's showdown. Despite playing in the toughest region, the Tar Heels had a 46.6% chance of winning these four games.

Add it all up, and there was a 4.8% chance- or 1 in about 21- that this would happen, given these opponents for each team. If you'd started with $100, and kept betting on the money lines of each #1 seed in each game, you would've turned that into $1,508. This final four combination was more unlikely than the results of any single team in the tournament. Davidson came the closest, as there was only a 6.1% chance of them reaching the Elite 8.

One thing I'll be interested to see is how this effects people's brackets next year. Until now, it was pretty unusual for someone (with the exception of Clark Kellogg) to have all four top seeds in their Final Four- after all, it had never happened before, so how could it? I'm sure the ESPN Tournament Challenge will have a lot more entries with an all chalk Final Four next year, even though the odds of that happening will be the same as they've always been.