Wednesday, September 21, 2005
Frontcourt Defense
Last week I started speculating about the importance of having tough post players to anchor a team's defense. It seemed to me that last season's leaders in overall defense (ranked by points allowed per possession) had imposing big men who were tall and could block shots and/or rebound well. No, it's surely not rocket science to those of you who have watched basketball for a few years - good defensive centers stop easy baskets near the hoop, which makes it hell for the offense to score points (see: Iowa vs Cincinnati last year).
Basketball minds like Dean Oliver and Dan Rosenbaum have agreed with the theory, at least as a general principle. In a recent article on individual defense in the NBA, Rosenbaum concluded -
Defensive ratings, on average, are highest for centers, then power forwards,If post players are generally the most important players to the defense, I want to explore some of the better frontcourt defenders from last year, and get an idea for which teams will be strong this year. There are of course no publicly available plus/minus data available for college teams, so Rosenbaum's technique is out (not that I'd go that in-depth). Instead, I'll take a far simpler approach. I'm just going to look at how well each team prevented its opponents from shooting on 2-point field goals, relative to each team's conference.
then small forwards, then shooting guards, and then point guards.
Offensive ratings go the other way. This squares with the conventional
wisdom that defense is anchored by big guys.
Clearly, this is no exact measure of the strength of a team's defensive frontcourt. Perimeter defenders can prevent and allow 2-point baskets as well. Not every 2-point attempt comes near the lane where a center might affect the shot. Likewise, some teams allow a lot of fast break points that are contested by no one.
In general, though, having good post players should lower the 2-point % a team allows, just as poor players would raise it. With zone defenses allowed, centers and big forwards spend a lot of their time on defense near the basket. They guard opposing centers when they post up, they can prevent the other center from getting good enough position for an entry pass in the first place, they help out when perimeter defenders get beat, and they challenge the shots of opposing players who grab offensive rebounds. Also, they prevent opponents from getting easy putbacks by boxing out and grabbing defensive rebounds.
For this little project I recorded each major conference's shooting percentage on 2-point field goals, then compared each team's 2-pt% allowed to their conference average (conference games only). The following table lists each conference's 2 -pt%, its leader in 2-pt% defense, and any other team that held its opponents at least 5% below the conference average.
Note - I often like to restrict these data sets to conference games so I can feel confident when comparing teams within each conference. When comparing teams from different conferences, be aware that not all are equal. Holding opponents to 40% shooting is probably easier if you play in the MAC than in the ACC.
Conference | 2-pt% Avg | Team | 2-pt% Def | Vs Avg |
Big Ten | 49.6 | Illinois | 46.7 | 2.9 |
ACC | 48.2 | North Carolina | 42.8 | 5.5 |
Duke | 43.2 | 5.0 | ||
Big East | 47.4 | Connecticut | 42.3 | 5.1 |
Big XII | 49.4 | Texas | 43.7 | 5.7 |
Kansas | 44.3 | 5.0 | ||
C-USA | 45.8 | Cincinnati | 39.6 | 6.2 |
Memphis | 39.7 | 6.1 | ||
Pac-10 | 49.4 | Stanford | 43.5 | 5.9 |
SEC | 49.5 | Alabama | 42.2 | 7.2 |
A-10 | 47.0 | St. Joseph's | 37.4 | 9.6 |
MVC | 48.3 | Southern Illinois | 45.2 | 3.1 |
WAC | 48.5 | Nevada | 42.2 | 6.3 |
MWC | 50.2 | Utah | 45.2 | 5.0 |
WCC | 47.6 | Gonzaga | 45.0 | 2.6 |
Does this pass the laugh test? I'd say so. Each of these defenses was anchored by a center or power forward (or both) with a national reputation for defense. There's at least 12-15 current/future NBA players who manned the post for those squads.
The more I watch basketball and follow the stats, the more I agree with Dean Oliver, author of Basketball on Paper, that basketball isn't composed of offense, defense and rebounding, but rather just offense and defense. He wrote that offensive and defensive rebounding are two different skills, and I agree. An offensive rebound is a contribution to the offense because it keeps a possesion alive, while a defensive rebound prevents scoring by ending a possession. Dean's idea became a little clearer to me when I realized that most team's that keep other teams' 2-pt% low also have good defensive rebounders. Additionally, post players make opponents miss by simply blocking their shots.
Here's some key contributors for each team, including their playing time, blocks per 40 minutes played, and defensive rebounding percentage. Asterisks (*) denote returning players.
Note - If the average team rebounds about 2/3 of the other team's missed shots, then each of the five players on that team would have a defensive rebound % of 13.4, if they rebounded equally.
Illinois
James Augustine*, 26.6 mpg, 1.8 bp40, 22.4 dRb%
Big Ten fans hoping for Illinois to disappear this year will likely be disappointed. Not only were the Illini the conference's best offense last year, they were also its second best defense, allowing only 95 PPP (points per 100 possessions). Augustine was overshadowed by the NBA-quality guards around him, but his presence in the middle solidified a tough defense. Illinois won't repeat last year's offensive showcase, but the return of Augustine and last year's Big Ten Defensive Player of the Year Dee Brown will make scoring difficult for anyone else.
North Carolina
Sean May, 26.8 mpg, 1.5 bp40, 26.3 dRb%
Marvin Williams, 22.2 mpg, 0.9 bp40, 21.8 dRb%
Building a college defense around two NBA lottery picks sounds like the way to go. (By the way, if was a GM with a high pick, there's no way Charlie Villanueva comes before May. He was simply a phenomenal rebounder last year.) It's hard to predict UNC's defense for next year with all the new faces, obviously.
Duke
Shelden Williams*, 33.6 mpg, 4.4 bp40, 22.1 dRb%
Shavlik Randolph, 18.9 mpg, 3.2 bp40
It's a testament to Williams's defensive ability that Duke's defense was this good, considering that J.J. Redick finished second on the team in total defensive rebounds. Adding the 6-10 McD's All-American Josh McRoberts should help considerably. Duke could easily be the nation's toughest defense, even with two freshmen seeing big minutes.
UConn
Josh Boone*, 29.5 mpg, 3.9 bp40, 15.0 dRb%
Charlie Villanueva, 25.8 mpg, 2.9 bp40, 20.3 dRb%
Rudy Gay*, 28.8 mpg, 2.6 bp40
Hilton Armstrong*, 12.4 mpg, 3.9 bp40
Hmm, I had no idea Gay had so many blocks last year. Look for him, Boone, and Armstrong to put the Huskies among the country's leaders in blocks once again.
Texas
Brad Buckman*, 25.5 mpg, 2.5 bp40, 22.4 dRb%
Lamarcus Aldridge*, 22.2 mpg, 2.7 bp40, 15.4 dRb%
P.J. Tucker*, 29.4 mpg, 16.3 dRb%
Jason Klotz, 28.9 mpg, 1.5 bp40
Luke Winn aptly pointed out how important Aldridge and Tucker were to the Longhorns last year. Lining them up beside Buckman will make Texas one of the country's toughest defenses, as well as one of its better rebounding teams.
Kansas
Wayne Simien, 34.3 mpg, 23.8 dRb%
Simien's injury history probably knocked him down a few pegs in the draft, but he was still one of the NCAA's best rebounders and a very efficient scorer. Did he really get picked after Linas Kleiza?
Cincinnati
Jason Maxiell, 31.4 mpg, 3.5 bp40, 13.9 dRb%
Eric Hicks*, 31.4 mpg, 2.9 bp40, 16.6 dRb%
I doubt one of these guys would seem all that tough alone, but in tandem they make for a ferocious defense, as Iowa found out in the first round of the tournament. It's interesting that neither was a big defensive rebounder, but they each blocked a lot of shots while committing relatively few fouls, which is probably an underrated skill. In fact, each their blocks/foul ratios are probably among the highest that I've seen, along with Shelden Williams and Josh Boone.
Memphis
Duane Erwin, 26.5 mpg, 2.3 bp40, 16.6 dRb%
Joey Dorsey*, 15.1 mpg, 3.1 bp40, 24.5 dRb%
Rodney Carney*, 29.8 mpg, 1.0 bp40
Memphis seems to be the hot pick to climb into next year's top ten. A defense built around Dorsey would be a good start, if he can bring down his astronomical 8.1 fouls per 40 minutes. His rebounding numbers were terriffic at both ends of the court - 18.6 oRb%, 24.5 dRb %, 21.6 Rb%. That's Sean May territory.
Stanford
Matt Haryasz*, 31.4 mpg, 1.5 bp40, 21.8 dRb%
Rob Little, 24.0 mpg, 17.6 dRb%
Did you know that Stanford had the second best PPP defense in Pac-10 play? Neither did I. They bring back their top three and seven of their nine top scorers.
Alabama
Jermareo Davidson*, 25.9 mpg, 2.3 bp40, 23.3 dRb%
Chuck Davis*, 33.0 mpg, 2.4 bp40, 14.5 dRb%
Neither of these guys were too foul-prone, which allowed 'Bama's defense to lead the SEC in opponents' eFG% and FTA/FGA. Only Kentucky allowed fewer PPP. Alabama didn't force many turnovers, so I'm thinking the defense won't miss Kennedy Winston that much (not that he had any steals anyway).
Nevada
Nick Fazekas*, 31.5 mpg, 2.0 bp40, 24.8 dRb%
Kevinn Pinkney, 29.2 mpg, 1.1 bp40, 18.7 dRb%
The defense should be solid again, with two seven-footers fighting for Pinkney's minutes. But who will score this year? Nevada's offense was only average in the WAC last year (102 PPP), and Fazekas is the only returning player with an offensive rating over 100 and at least 30 shots last year.
Gonzaga
Ronny Turiaf, 30.8 mpg, 2.4 bp40, 22.1 dRb%
Just the opposite of Nevada. The offense should be excellent, again, but it'll be interesting to see if they can improve on last year's league average defense (102 PP in the WCC) after losing Turiaf. Might be the most overrated team (top 5, really?) this side of West Virginia.
Well there you have it - some of the best frontcourt defense in the country from a year ago. Please email me if you have any questions, or just want to tell me I went about this all wrong. I'm stopping a little abruptly, but I'm sure this won't be the last time I pick up this topic.