Tuesday, December 18, 2007

Measuring Damian Johnson's Impact

Through eight games, Damian Johnson has been the most valuable player for Tubby Smith's first team in Minnesota. While he hasn't gotten the headlines that come with a massive scoring output, Johnson has done the things that go mostly unnoticed by fans skimming through boxscores.

Johnson has received plaudits from those of us in the blogosphere and some passing praise in the mainstream media. But to really see Johnson's impact beyond the traditonal boxscore, we have to dig deeper, and that means looking at statistics in a more scientific manner, and going beyond the generic categories like blocks, rebounds and steals.

Ken Pomeroy's recent article at Basketball Prospectus on identifying the college game's best defenders notes that blocking shots AND forcing steals "is a strong indicator that a player is doing disruptive things on those possessions where he doesn't get credit for doing either." Those of us who have watched every minute of the Gophers this season know that one player falls into that category: Damian Johnson. Pomeroy continues and explains what benchmarks to look for in the blocks and steals percentages statistics:

Specifically, the numbers I look for are a block rate of at least 6.0 with a steal rate of at least 2.5. In fact, these benchmarks are probably too lofty. I've been tracking these stats for the past three seasons, and only two players playing at least 24 minutes per game in power conferences getting have been able to reach these figures. Those players are Joakim Noah (who did it twice) and Shelden Williams, who were both among the best defenders in recent years. ... So far this season, there are just three players from power conferences meeting [this] threshold: Kansas sophomore Darrell Arthur, Nebraska senior Aleks Maric and LSU freshman Anthony Randolph.
The only thing standing in Damian Johnson's way of joining that trio is a few minutes per game. During the 7-1 Minnesota start, Johnson has averaged 20 minutes per game. Meanwhile, Johnson has put up an impressive block rate of 10.4 (good for 39th in the country) and a steal rate of 4.0 (good for second on the team behind point guard Al Nolen.) This tells us that Johnson, as Pomeroy wrote, is doing "disruptive things," on possessions when he's not given credit for a block or a steal.

If you're not familiar with the block rate and steal rate staistics, they are relatively straightforward. A block rate is the percentage of two-point shots that are blocked by the player in question when he is on the court. The steal rate is the same. That means that on about 15 percent of opponents possessions, Damian Johnson has been racking up a block or a steal. But, again, as Pomeroy noted, the numbers tell us that Johnson is is being a large disruptive precense on countless more possessions.

Johnson has been the Gophers' best player defensive end of the floor. But his hustle and effectiveness can also bee seen on the offensive end of the floor.

Using offensive rating, Johnson is the 4th most effective player the Gophers have. More impressively to me is the offensive rebounding percentage, where, again, Johnson leads the Gophers. This statistic is found by dividing the number of offensive rebounds by the total number of missed shots when a certain player is on the floor. Essentially, it shows us how efficient someone is at claiming offensive rebounds. Johnson, again, leads the Gophers with a 13.9 (good for 82nd in the country). Johnson might not be putting up Blake Hoffarber-like offensive numbers, but creating second-chance opportunities is as valuable, if not more, than shooting a high percentage from beyond the arc.

By using this statistcal analysis, Johnson is clearly the most active Gopher on the defensive end, and he's done the most, while playing off the bench, to secure second-chance opportunites for the Gophers. It will be interesting to see how much these numbers fluxuate when the Big Ten season begins. But through the 7-1 start, Damian Johnson is your MVP.

(Note: All of the stats cited in this post can be found here.)