Posted by Jonah Gardner on March 9, 2016
Have you tested your office computer's streaming capabilities? Made sure your Venmo account is all set? Refamiliarized yourself with terms like Net Rating, Simple Rating System, and RPI? If not, you'd better get on it, because March Madness is almost here!
This Sunday, the Selection Committee will announce the 68 teams that comprise this year's race to the Final Four. And, immediately following that, millions of people will begin filling out their bracket. Every year, you carefully research the teams, read up on the players, scout the tactics, and then inevitably see your bracket obliterated in the first weekend when FREAKING DUKE LOSES IN THE ROUND OF 64 AGAIN.
That's not going to happen to us this year. This year, we're not going to listen to why the experts think Loser State is a trendy pick to win it all or Mid-Major A&M might be this year's March Madness Cinderella team. We're not even going to worry about which teams are in the bracket. Instead, we're going to let the cold hard facts of NCAA bracket history tell us which seeds tend to do well, and go from there.
Two quick notes here. First, all the stats we're using, unless otherwise marked, run from 1979-2015 and come from the NCAA Tournament Game Finder on College Basketball Reference. Second, if you use this information to construct a perfect bracket, you are legally required to give me half the winnings.
In the Round of 64, it won't surprise you to learn that having a higher seed usually helps. The lower seeded team only wins 25.5% of the time in the Round of 64, meaning that upsets happen around 1 in every 4 games. But, as you'd assume, they're not evenly distributed across all the games. Here's the Upset % by matchup:
You can draw a pretty sharp line between the 12 and 13 seed. None of the 13-16 seeds upset the 1-4 seeds more than 25% of the time, while 9-12 all win at a rate well over 1 in 4. In other words, if you're picking every 5-8 seed to go chalk, you'd better have a good reason.
We can also look at the point differential in these matchups in order to set a kind of betting line on these games:
As you can see, the average 16 seed would be a 24.5-point underdog against the average 1 seed. On the other hand, the average 8-seed wins by 0.5 points, making those games essentially toss-ups.
This can help you identify possible early upsets. If, for example, a 4-seed is only favored by 7 or 8 against the 13, they might be weaker than the average 4-seed. Even if you think they'll win that game, you can keep in mind that they may be susceptible to an upset or early exit down the road.
Once you make it out of the Round of 64, a favorable path forward is the key to a deep run. Here, for example, is the percentage of the time each seed advances:
There's a big difference between the 1-seed, which advances to the Sweet Sixteen 85% of the time, and the 2-4 seeds. In fact, with a 48.6% advance rate, the 4-seed misses the Sweet Sixteen more often than it makes it; meanwhile, the 3-seed's chances, 52.0%, are just a little better than a coin toss.
If you want to identify potential Cinderellas in the Sweet Sixteen, you should be taking a close look at the 10-12 seeds. In the case of the 10-seed, don't let the double-digits psych you out. As we saw in the first round, 10-seeds tend to be, on average, 3 points worse than 7-seeds, which is roughly the difference between the Kansas Jayhawks and Oklahoma Sooners this year, according to SRS.
Regardless of whether the 7 or 10 wins in the Round of 64, both go on to win their second game, almost always against a 2-seed, at an identical rate. Whether you're a 7 or a 10, your chances of making the Sweet Sixteen are 17.6%.
While 11 and 12 seeds are around 1-in-8 shots for the Sweet Sixteen (12.5% for the 11 and 13.9% for the 12), they're still better bets than the 8 and 9 (10.1% and 4.7%, respectively). That's because an 11 or 12 will face a 4 or 3, teams that advance to the Sweet Sixteen only around 50% of the time, while the 8 or 9 will end up facing a 1 and 1-seeds advance 85% of the time.
Using that same logic, it makes sense that the 12-seed would have a slight edge on the 11, given that their second round matchup is against a 4-seed, while the 11-seed would have to play the 3.
At the same time, if you believe in an 8-seed, you should ride them as far as is reasonable. 8-seeds get into the Final Four around 4.1% of the time, more than 7-seeds (2.0%) and equal to 6-seeds. This makes sense since, if you've taken out the 1-seed, you've already beaten the toughest team in your bracket, and you also get to follow the slightly easier path that 1-seeds get.
The key, of course, is identifying the 1-in-10 8-seed who can knock off a 1-seed, although there are a few signs.
Some, like the 2014 Kentucky Wildcats, were drastically underseeded. Despite being an 8-seed, SRS ranked the Wildcats as the 15th-best team that year. On the other hand, the 2000 Wisconsin Badgers, though slightly underseeded, were also lucky to face an Arizona Wildcats team that was 14th in SRS, rather than Top 4. Lastly, some teams just get hot. That's really the best explanation for how the 2011 Butler Bulldogs, ranked 52nd in SRS, knocked off a 1-seed with the 4th-best SRS in the nation.
For a different way of looking at it, here's the breakdown of teams that play in each round, by seed (click to see the bigger version):
The deeper into the tournament you go, the more you want to rely on the top-3 seeds. 68.2% of teams that have reached the Elite Eight, 81.1% of teams that played in the National Championship, and 86.5% of champions were seeded in the Top 3.
On the other hand, if you're into a Cinderella, you probably want to ride them to the Final Four. While the 1-seed's percentages steadily climb the deeper into the tournament you get, the 2 and 3 seed's shares actually drop from the Elite Eight to the Final Four. In contrast, the 4, 5, and 8 seeds all constitute a larger percentage of teams in the Final Four than they do in the Elite Eight.
In summary, we're looking hard at 10-12 seeds this year. We're also only picking an 8-seed we truly believe in, and picking them to go far. And, at the end of the day, we're putting romance aside and looking for a Top-3 team to cut down the nets while "One Shining Moment" plays.
And, after all that, we're still going to lose to the person in the bracket pool who picked their alma mater.