Get inside March Madness with SI.com's Luke Winn in the Tourney Blog, a daily journal of college basketball commentary, on-site reporting and reader-driven discussions.
3/18/2008 04:08:00 PM
Bracket Math, Part Two
UCLA fans are praying that Kevin Love's back pain isn't an issue during the dance.
NEW YORK -- Having picked UCLA to win the national title, I'll admit I'm just as concerned about Luc Richard Mbah a Moute's ankle and Kevin Love's back this week as I am about statistics. But it's become an annual tradition around these parts to do an efficiency breakdown of the bracket, attempting to ID the real Final Four contenders and the potentially vulnerable high seeds, so that's what the blog is serving up in today's Bracket Math lesson.
Efficiency is measured by how many points a team scores and yields per 100 possessions rather than per game, as compiled and adjusted for competition by kenpom.com. The reason these numbers matter so much is because they allow us to remove tempo from the equation, and evaluate all 341 Division I teams -- regardless of their game pace -- on the same level. The table below presents strong evidence (despite the small sample) of how much efficiency matters in the NCAA tournament. From 2004-07, only two teams outside the top 49 in defensive efficiency made the Elite Eight, and zero teams outside the top 25 made the Final Four.
Efficiency Profile of Elite Eight Teams, 2004-07
Adjusted Off. Eff. (Nat'l Rk.)
Adjusted Def. Eff. (Nat'l Rk.)
NCAA round key: NC = national champ, RU = runner-up, FF = Final Four, EE = Elite Eight.
The point here is not that we can guarantee 2008's Final Four teams in advance, but rather that it's a good idea to pick clubs with good offenses and defenses around the Top 25. Of my Final Four, UCLA ranks fourth in adjusted defensive efficiency (ADE), while Kansas is third, Texas is 32nd and Tennessee is 34th.
The larger point of the chart above is that it's not at all smart to put defensively challenged teams in your Elite Eight. Examine the 1-8 seeds from 2005-07 who ranked below 75th in defensive efficiency, you'll see that only West Virginia, which bombed threes at an insane rate in the '05 tourney, cracked the Sweet-16 ceiling:
2005's defensively challenged 1-6 seeds:
Team Off. Eff Def. Eff. (Seed) (Nat'l Rk.) (Nat'l Rk.) Rd. Out LSU (6) 112.1 (22) 94.7 (84) 1 Gonzaga (3) 115.5 (10) 97.0 (119) 2 W. Forest (2) 120.8 (2) 94.0 (76) 2 W. Virginia (7) 116.1 (15) 96.8 (86) EE
Vandy's main deficiency on D in last year's tournament was not being able to stop Jeff Green from traveling on Georgetown's final shot ... but still, the 'Dores did not become the next version of '05 West Virginia.
The interesting thing about the '08 bracket is that there's only one 1-8 seed with a sub-75 defensive efficiency ranking ... and once again, it's Vandy. So we'll cast the net a little wider, to 1-8 seeds with sub-60 ADE, to provide you with a few more teams that aren't great sleeper Elite Eight picks:
While this quartet has some real offensive firepower, I didn't pick any of them to go past the second round. It's also worth noting that Oregon, which was handed a No. 9 seed, is the worst major-conference defensive team in the entire NCAA tournament. The Ducks rank 125th in ADE. I don't recommend picking them against Mississippi State.
With that out of the way, we can turn to the reasonable pool of Final Four squads, whom I've broken down into three flights:
Team Off. Eff. Def. Eff. (Seed) (Nat'l Rk.) (Nat'l Rk.)
Flight A: Top-10 in AOE and ADE Kansas (1) 126.6 (1) 83.6 (3) UCLA (1) 120.7 (5) 84.5 (4) Duke (2) 119.7 (7) 87.4 (10)
The numbers make a Kansas-UCLA title game appear to be a likely scenario (although I took Tennessee-UCLA). But the chart above also shows that Clemson -- a team I like to reach the Sweet 16, at least -- might be the most dangerous squad outside the 1-4 lines. Could the Tigers spoil Kansas' run to the Final Four? Or will the Jayhawks make their statistical prowess matter in the dance? And the biggest question of all: Will you guys use any of this stuff to beat me in the Tourney Blog Pool?
One point worth noting is that team's average efficiencies can vary over the course of the season. Since these efficiency ratings are normalized to average competition, they should only change as a result of improvements (or declinations) of teams.
I haven't done a lot of looking at the temporal dynamics of efficiency, but I have noticed a couple things in the last few days:
1. Duke's efficiency ratings are dropping. Earlier in the year, they were rated higher but have fallen. Their average efficiency for the season still looks pretty good, but their efficiencies in the last two weeks are much worse.
2. Wisconsin started the season at #1 in defensive efficiency, then dropped to #4 in the middle of the season. Now, they're back to #1. In the last 9 games, they have held 8 opponents to less than 60 points and 4 opponents to less than 50 points, including one to 41 and one to 34.