A look at what John Groce means when he talks about efficiency.

By now, you've no doubt heard Illini basketball coach John Groce talk about "efficiency" when he discusses how well his team is playing. You'll often see writers mention "tempo free" statistics when talking about how efficient a team is, both on offense and defense. These types of statistics have been around for a long time. Dean Smith, the hall-of-fame coach [3] at North Carolina, was the first to really use stats like points per possession to measure how well his teams were playing. Smith started asking the question, "how well are we playing on each possession?" to try and make his teams more efficient (and to keep the opponents from being efficient) on offense. Because tempo in each game can fluctuate wildly (picture playing Indiana vs. playing Wisconsin), Smith started looking at his team's performance on a per-possession basis.

If you're looking for a good primer on what tempo free statistics you'll frequently see discussed, here is a good one from the folks at the Michigan State fan site theonlycolors.com [4]. It's appropriately titled "Tempo-Free Stats for Dummies [5]," and gives a good summary of what stats are used, why they're used, and some good benchmarks to separate good performance from bad.

Finished reading? Good. As KJ mentions in that article, there are some really good resources online if you'd like to keep up with how the Illini are doing in the "tempo free" world. One of them happens to be from a University of Illinois alumnus, John Gasaway. He's been working with tempo free stats for quite some time, starting with the Big Ten Wonk website several years ago. If you were able to follow along with the "Dummies" article above, then take a look at John's more detailed look at tempo-free stats, "This is TFS: tempo-free stats [6]." He's since moved to Basketball Prospectus [7], where he writes regularly. Much of his work requires a subscription (totally worth it, by the way), but he has a weekly column called "Tuesday Truths [8]" that is available for free. Here's the most recent edition [8], which he posted this Tuesday 2/12. Some of Gasaway's columns are also available at ESPN.com, but only for "Insiders."

The other guru of tempo free stats is Ken Pomeroy, who you can find at his website kenpom.com [9]. His home page gives you a snapshot of rankings for all of the teams in NCAA Division One. As of today, after the Purdue win, he has Illinois ranked at #32, which is up nearly ten spots from where they were before last night. Here's his brief explanation [10] of his ratings system. I suggest you read the other primers above before diving in too deeply. Full disclosure: when he starts talking about things like "log5 formula [11]", I tend to go a bit crosseyed. But, for the more mathematically inclined among you, enjoy yourselves.

Meanwhile, here's a look at his rankings as of this morning. He's got Florida as his best team as of today, with Indiana #2. Just click to enlarge the screen shot, or you can go to kenpom.com to see rankings of all division one teams.

As for how the Illini are faring in Big Ten play, the aforementioned "Tuesday Truths" from John Gasaway provide thebest snapshot there, and it's useful to see how the teams are faring in conference play, since non-conference schedules can vary so wildly. Note that these rankings were done before the blowout win by Michigan State over Michigan, and before the Illini's destruction of Purdue last night. Again, just click to enlarge, or click the link mentioned above to see John's complete article.

**UPDATE: **Thanks to regular HQ reader JimOATSfan, who pointed out a great stats site below in the comments, I'm able to update John Gasaway's Big Ten efficiency stats through games of last night. If you compare Illinois' numbers from Tuesday to their numbers today, you can see that the Illini have made progress. By the way, I'm not sure I mentioned this, but the EM you see in both John's article and in my table below stands for "efficiency margin," which is simply the difference between a team's Offensive Points per Possession and their Defensive Points per Possession. You can see that the Illini offense has been slightly above average in Big Ten play, while their defense has been below average, though both numbers have improved a lot in the last week. Click to enlarge.

Now, let's take a look at how the Illini did in these tempo-free stats in their game last night vs. Purdue. As you might expect in a blowout win, Illinois did pretty well, but let's take a closer look.

- Illinois PPP (points per possession): 1.19 (1.01 is average in the Big Ten this season)
- Illinois effective FG% (takes into account higher reward on 3pt shots): 47.7% (average is about 49%)
- Illinois turnover percentage: 16.5% (average is about 20%)
- Illinois offensive rebounding percentage: 50.0% (average is about 33%)

Now, how did the Boilermakers do in their tempo-free stats? Um, not so well.

- Purdue PPP: 0.90
- Purdue eFG%: 43.6%
- Purdue turnover percentage: 25.9%
- Purdue offensive rebounding percentage: 36.8%

Illinois did a great job of taking care of the basketball and of getting offensive rebounds last night, giving them many more possessions than Purdue had last night. When you add in the Illini's four-percent edge in effective FG%, you can see how the Illini were able to win this game comfortably.

So, does any of this make sense? Do you care? I'll try to post a quick tempo-free wrapup after each Illini game the rest of the season. Looking at these stats from time-to-time has given me a bit better understanding of the "why" and "how" behind some of the results for the Illini this season, and I hope it can do the same for you.

Of course, stats are only part of the story. No stat can be as much fun as this:

- Channeling his inner Knight

Or this:

- Violent Tyler Griffey!

Thanks for reading. Talk to you soon.

bmoline@wdws.com [15]

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