A couple months ago, KenPom added something called “defensive fingerprint” on each team page. Mr. Pomeroy’s explanation:
Defensive Fingerprint attempts to objectively identify the style of a team’s defense. Inputs into the system are the departure from the D-1 norm of the following defensive characteristics…
- assist percentage (triple weight, higher means a more likely zone team)
- 3-point attempt percentage (triple weight, higher means a more likely zone team)
- free throw attempt percentage (double weight, higher means a more likely man team)
- turnover percentage (single weight, higher means a more likely man team)
- defensive rebounding percentage (variable weight depending on offensive rebounding percentage, higher means a more likely man team)
All those factors go into a super-secret formula that calculates whether, based on its stats, a given team is likely a zone team or a man-to-man team.
What’s interesting is that, despite the fact that MSU played man-to-man defense for all but a handful of possessions this past season, the formula spits out an “inconclusive” on our team page. To investigate this phenomenon, I’ve put together a table showing MSU’s rankings for the five stats used in the formula. The first set of numbers are the full season; these are the numbers that KenPom is using.
| All Games/National Rank | |||
| MSU Value | MSU Rank | Indicates | |
| Assist % | 52.4 | 131 | Neutral |
| 3PA/FGA | 35.8 | 271 | Zone |
| FTA/FGA | 36.5 | 178 | Neutral |
| TO% | 19.9 | 190 | Neutral |
| Opp OReb% | 27.3 | 11 | Man-to-Man |
You can see why the formula can’t identify us as a man-to-man team. Our opponents shot a lot of 3-pointers, which makes us look like a zone defense. But we ranked 11th nationally in defensive rebounding percentage, which implies that we play man-to-man defense. For the remaining three factors, we’re very near the national averages, so the formula has nothing to go on.
One reading of these numbers is that Tom Izzo’s defensive scheme got the best of both worlds this season:
- By placing in emphasis on preventing dribble penetration by hedging off shooters, the team forced a lot of perimeter shots from its opponents (the primary benefit of a zone defense).
- But the fact the team was fundamentally playing man-to-man defense, particularly on the interior, meant the team didn’t sacrifice anything in terms of defensive rebounding (generally the main weakness of a zone defense).
Before declaring victory in the age-old quest to find the perfect defensive scheme, though, I think we meed to get a little more definition on those three middle-of-the-road formula factors. To do so, I pulled the same numbers for conference games only (with ranks within the Big Ten).
| Conference Games/Rank | |||
| MSU Value | MSU Rank | Indicates | |
| Assist % | 54.2 | 2 | Man-to-Man |
| 3PA/FGA | 32.4 | 9 | Zone |
| FTA/FGA | 34.7 | 7 | Man-to-Man |
| TO% | 20.7 | 8 | Zone |
| Opp OReb% | 24.7 | 1 | Man-to-Man |
For assist percentage and free throw rate, we look more like a man-to-man team. For turnovers, we look more like a zone team.
I’m not sure the low assist percentage is necessarily a major asset or weakness. But the other two numbers are unfavorable. Playing physical man-to-man defense resulted in a relatively higher number of fouls that created additional free throw opportunities for our opponents. At the same time, the fact that our perimeter defenders were more focused on preventing penetration than with disrupting our opponents’ offensive rhythm meant we didn’t create a lot of turnovers.
Overall, then, we had one strength (defensive rebounding) and one weakness (fouling quite a bit) generally associated with man-to-man defense and one strength (forcing perimeter shots) and one weakness (not creating turnovers) generally associated with zone defense.
On net, the way this team played defense obviously worked pretty well, as they finished the season ranked 10th in the country in adjusted defensive efficiency. Most of the numbers above are pretty consistent with the team’s numbers over the past several seasons, indicating that Tom Izzo’s approach to defense hasn’t changed much in recent years. The biggest change from 2007-08 to 2008-09 was an increase in defensive rebounding percentage of roughly 4 percentage points. As one might expect with a Tom Izzo-coached team, the key to success was rebounding.
P.S. You can probably sense I’m stalling for time by throwing a lot of numbers at you. There’s been a bit of a delay in getting the new site launched. It should be ready to go late this week or first thing next week.
your data fits one’s intuition. I’ve always been curious about MSU’s foul proclivity. Is it slow feet and sloppy hands, or is there some purpose to it? In other words, does Izzo preach a more physical defense on purpose on the assumption that his teams are deep and refs in the end will let the team get away with it. I was struck once again, in the NCAAS, that MSU was called for a substantially higher number of fouls in virtually every single game. UNC shot 40 foul shots, for instance.
admit it, KJ. You’re having second thoughts. And missing the old site already….
To hubert’s question (which is a good one, I think) why does MSU foul so much? Teams like Illinois and Purdue aren’t more athletic than us and appear to be excellent defensive teams as well. Yet they don’t seem to foul as much as MSU does. I would believe the data if you showed me, but that’s my impression.
Furthermore, Wisconsin is notrious for playing excellent defense and routinely making more FTs than their opponents shoot.
So is it slow feet? Lack of awareness? Is it the result of some strategy issue like Izzo generally not doubling in the post or only helping out if someone gets into the lane?
I’m curious to hear your thoughts.
kj is getting cold feet. This site got us to the Championship game!
Could the fouling be a factor of the physical defense?
Wisconsin of last year had basically the same D we had this year minus the foul proclivity. I would guess that if you looked at UConn’s stats, they would look a lot like Wisconsin of last year, or us this year minus the fouls plus more blocks and a lower opponent 2 point FG percentage (thanks to Thabeet). This year Wisconsin fouled more and their defensive efficiency suffered for it. I think their secret last year was Flowers, who was a special defender.
I’m normally a fan of Ken Pomeroy metrics but I’m not sure a bifurcated zone – man to man defensive fingerprint metric tells you a whole lot if a team like MSU or Wisconsin, both of which play almost exclusively man to man defense, show up as inconclusive (although on Kenpom.com’s MSU scouting report we are identified as mostly man despite being one zone/one man/ the rest neutral on the components that make up the metric). The individual metrics tell you a lot, but the fingerprint apparently isn’t accurately identifying the type of D teams play.
We were pretty middle of the pack in terms of foul calls this year – it was a relative weakness (especially compared to our defensive rebounding) but we were not a particularly foul-prone team at 178 – that’s pretty much mediocre. I think the reason we aren’t better is that Izzo wants us to contest shots and agressively fight for position in the post to make sure we don’t give up easy looks in the paint and are in position to get the rebound when a shot goes up. Another part of it may be that Izzo would rather have us foul than give up an easy 2 points, given that we had the depth to absorb the fouls. It’s when you foul and give up the and-one that’s the problem in that scenario – if you are going to foul a guy who gets into the paint make sure he doesn’t make the shot.
As for the foul disparities in the tournament – against UNC and UConn they were to be expected based on the stats – both teams rank in the top ten (UConn is number one) in opponent FTA/FGA, and both teams are pretty good at drawing fouls, especially UConn. We actually drew fouls at a slightly better clip than UNC (we were 50 they were 75), surprisingly. Louisville is top 20 in opponent FTA/FGA, but they don’t draw many fouls themselves to you would have expected that game to be a wash. USC is further down the list but still ahead of us on both drawing and committing fouls. Kansas is about dead even with us on the metrics. Based on that we should have been about even with KU and Louisville on fouls and UConn and UNC should have gotten the better end of the deal. Looking at the actual game stats we got the better end of the FT% deal against KU and USC – Louisville won that metric against us which is surprising, but it is surprising that we came out ahead against USC. Against KU we came out pretty much even so that game played out as expected.
Thanks, Marc, that was illuminating. I still wonder how much of it is by strategy, and how much is the personnel Izzo has had.
I’m sure that this has already been discussed already, but I’m not searching. When you switch to the new site, will the title banner make the move too? And are you planning on adding anybody from this year’s team to it?
The SB Nation sites have logos, rather than banners. Plus, we’ll be more balanced between football and basketball. So the SW banner will have to be retired. Had it lived on, Kalin Lucas was a slam dunk to be added at some point.
That is devastating news.