Behind the Numbers: Against the Numbers

Posted by KCarpenter on March 15th, 2011

This is the one time of the year where people take an incredible interest in college basketball statistics. Folks who don’t know their Ken Pomeroy from their Jeff Sagarin rankings are suddenly asking how valuable a low turnover percentage is and if there is any evidence it correlates with tempo despite being allegedly tempo-free. Fortunately, there are lots of smart stat people who are willing to lend an analytic hand. If that’s what you are looking for, then let me point you in the right direction. 

Sullinger & His Buckeyes Perform Well in the Metrics

I obviously place a great deal of trust in respect in Ken Pomeroy’s statistical rankings that use Pythagorean expectation-based offensive and defensive efficiencies. Well, Ken has upped the ante by running a log5 analysis of the tournament field which breaks down the expectation of a given team to reach each round. Even more fun, Neil Paine at Basketball Reference ran Monte Carlo Simulation of the tournament 10,000 times using Pomeroy’s values and posted the very interesting results. Jeff Sagarin’s list uses scoring margin and a clever use of the Elo rating system (originally designed to rank chess players) to come up with his list of things to pick. Naturally, Nate Silver can’t resist weighing in with his method of making picks, which basically does for March Madness what Five Thirty Eight did for electoral math. His system, much like his polling methodology, is a weighted aggregation of different sources like Ken Pomeroy and Sagarin’s ranking plugged in with other factors that Silver thinks are important like geography, player ranking, and pre-season ranking. The sources he pulls from are exhaustive and smart while his methodology is well-reasoned. That said, it’s worth mentioning that a dumb “wisdom of the crowds” type list, such as ESPN’s national bracket (an average of all individual brackets) tends to outperform the majority of individual brackets.

Now, here’s the question: are you trying to predict the winner of games or are you trying to win a pool? These are not the same thing and it’s important to make the distinction. The national bracket, as I mentioned, usually gets a lot of the answers right. For the big questions, common sense is usually close enough. You want to know who has the best chance of winning the NCAA? Ohio State.  Pretty much every system, rankings, and analytics have Ohio State as the best team in the country. I happen to think this as well. I also think that the four number one seeds have the best chance of making it to the Final Four. Lots of folks agree with me and lots of analytics back it up.

Read the rest of this entry »

Share this story

Profiling Elite Eight and Beyond With Pomeroy

Posted by rtmsf on March 17th, 2010

This is an idea we’ve had bouncing around in the dome for a while now, and since we’re not smart enough to actually do a bunch of number-crunching analysis with regression formulas and all that other statistical nonsense, we’re going to do what we know how to do — eyeball it.  (note: if you want a more data-driven analysis, visit Vegas Watch for a region-by-region breakdown)  We’ve taken a look at the Pomeroy numbers for the last five seasons (2005-09) to get a sense as to the type of offensive and defensive efficiency numbers that constitute your typical Elite Eight/Final Four/Runner-Up/Championship team.  We know that all of these teams are pretty darn good — but can we draw any conclusions based on the past five years of historical data that might give us a clue as to how we should be looking at this year’s bracket?

Here’s the list of roughly thirty or so teams with the strongest efficiency differentials in the 2009-10 season (sorted as such): that far right column is the key number for our purposes.  The greater the efficiency differential, the more dominant a team tends to be.  Remember that both the offensive and defensive efficiency statistics represent the number of points a team scores over 100 possessions of basketball.  +120 is really good for offense, while less than 90 is really good on defense.  Anytime a team’s differential approaches +30 points or more, we’re reaching rarefied air in college basketball.  (note - Pomeroy doesn’t provide historical data prior to past years’ tournaments, but we still think there is some value in looking at his final ratings because the likelihood that a team significantly improves or regresses during the snapshot window of the NCAA Tournament is small).  If you don’t follow Pomeroy regularly, you might be a little surprised at the placement of certain teams versus some others.  Have a look…

 
So what, right?  Well, let’s see if we can use the historical data that we have from Pomeroy to make assessments of this year’s batch of teams and their prospects. 

National Champions

Let’s first take a look at the last five national championship teams.  What jumps out at us immediately is that they’re all offensive juggernauts.  Every one of them is ranked first or second in offensive efficiency.  These teams know how to score the ball.  Defensive efficiency is a little more spotty, but they’re all pretty good (<90 and ranking in the top twenty).  The average differential is really high at 37.4 points per 100 possessions, and all of them easily reach the +30 threshold in that regard.

Read the rest of this entry »

Share this story

Statistically Confirming the SEC is Garbage

Posted by rtmsf on December 5th, 2008

During the nonconference portion of the season we can use the cross-pollination among the BCS teams as well as their games against the mid-majors as an early warning system of sorts to determine which conferences are the strongest in a given year.  Last year the Pac-10, for example, got off to a strong start, and by and large that conference was considered the best in the nation throughout most of the 2007-08 season.

Believe it or not, we’re already one-quarter of the way through the regular season (and halfway through the nonconference slate), so we have plenty of raw data to start making those determinations.  From what we see thus far, it appears that there are three grades of power conferences, with the ACC & Big East at the top, the Big 10 and Big 12 in the middle, and the Pac-10 and SEC pulling up the rear.  For confirmation, take a look at the table below.

conf-h2h-1205081

Data Source:  basketballstate.com

Read the rest of this entry »

Share this story