Editor's note: The College Basketball Prospectus 2009-10 is now available on Amazon. In addition to having the best previews you'll find anywhere of the ACC, Big 12, Big East, Big Ten, Pac-10, and SEC, the book's also chock full of informative and indeed innovative essays on the game in general. Like this one by Ken Pomeroy, one that--Blair's knees notwithstanding--a good many NBA GMs could have profited from reading before draft night.
Much of my interest in quantifying things comes from the desire to be aware when something crazy happens. Without some context of whatís normal, thereís no way to know whatís abnormal.
Unless you were paying close attention to advanced stats, you probably didnít realize that Pittís DeJuan Blair may well have had a season for the ages in 2008-09. During his time on the floor, Blair pulled down nearly one in four of his teamís missed shots. The exact figure was 23.6 percent. Thatís a number that by itself isnít all that significant, so letís put it in perspective.
- The next highest offensive rebounding rate last season was turned in by Santa Claraís John Bryant at 18.6 percent. Bryant would have needed to grab 35 more offensive rebounds to match Blair.
- In our five seasons of tracking this data, the next best rate was posted by Morehead Stateís Kenneth Faried in 2007-08 at 20.3 percent.
- Only 40 players in the country had a better defensive rebounding rate last season.
- In 6,700 player-minutes, the University of Colorado grabbed a total of 201 offensive rebounds last season. In 955 minutes, Blair by himself pulled down 195.
Let it be known that Blairís season was historic. Even though offensive rebounding like this has been observed now once in five seasons of tracking, itís plausible that a season this extreme is far rarer than that. A season like this deserves a complete examination, if for no other reason than to preserve its greatness in print for future generations. But also to answer a more fundamental question: Exactly how valuable was Blairís performance? How valuable was the best offensive rebounding season that weíve (possibly) ever seen?
I put my team of number-crunching robots to the task of looking at each one of Pittís possessions in an effort to answer those questions.
Finding 1: Blair came by his record honestly, except for one case.
What I thought I would find is that Blair had incidents where he racked up multiple offensive boards through a sequence of missed layups or tip-ins. However, Blair didnít benefit from many of these situations. In fact, only once during the entire season did he record as many as three offensive rebounds in a single possession. It occurred in the January 14 game against South Florida. I specifically say ďrecordedĒ three rebounds because in this particular instance, it appears Blair was given one that he didnít deserve. Here are the details of that possession from the gameís official play-by-play:
07:15 Beginning of Possession (Score: Pittsburgh 66, South Florida 53)
07:15 REBOUND (DEF) by Fields, Levance
07:01 MISSED JUMPER by Fields, Levance
07:01 REBOUND (OFF) by Blair, DeJuan
06:55 MISSED LAYUP by Blair, DeJuan
06:55 BLOCK by GILCHRIST, Augustus
06:52 REBOUND (OFF) by Blair, DeJuan
06:51 FOUL by GILCHRIST, Augustus (P3T8)
06:51 MISSED FT SHOT by Blair, DeJuan
06:51 REBOUND (OFF) by Blair, DeJuan
06:51 GOOD! FT SHOT by Blair, DeJuan
06:51 End of Possession (Score: Pittsburgh 67, South Florida 53)
If you follow the possession through, you should notice something unusual near the end of it. Blair goes to the line after getting fouled by the Bullsí Gus Gilchrist (who, by the way, had his best game of the season, scoring 22 points in 32 minutes off the bench). Blair misses the first, gets his own rebound, and is suddenly back at the line shooting again without another foul being recorded. He makes that free throw and then the Bulls get the ball for some reason.
What I expect happened here was that Blair was at the line for two. Normally, when a player misses the first free throw in this situation, the scorekeeper will record a team deadball rebound for accounting purposes, which gets dropped on the floor when the official box score is created. However, a rebound was erroneously assigned to Blair while he was simply standing at the line waiting to get the ball for his second attempt.
This serves to illustrate that all stats are measurements and all measurements have errors. Blairís official total for the season was 195. He probably didnít have that many offensive rebounds. He may not have truly had 194, either--undoubtedly there were other cases where either a teammate was credited with a rebound Blair got, or vice versa. College basketball is a fast-paced game and stats are recorded by people not getting paid much to do it. Because of that, the precision of large numbers accumulated over the season should not be taken for granted.
Regardless, DeJuan Blairís 195 offensive rebounds were spread across 178 possessions. While he got help from the scorekeeper on one occasion, it would appear he did little padding of his own stats.
Finding 2: Blair's boards were very good for the Pitt offense.
Part of the reason for this exercise was that I thought Blairís efforts were quite valuable. I mean, Iíve always felt like the offensive rebound is an underappreciated play. For instance, the blocked shot gets incredible publicity. It can erase points, but it also doesnít necessarily end a possession. Likewise, an offensive rebound erases a missed shot. It doesnít necessarily lead to points but it gives the offense an opportunity for points that it otherwise wouldnít get.
I suspect the reason that the block gets all the attention is that (a) itís exciting, and (b) itís more rare. There were about three times as many offensive rebounds as blocked shots last season. In addition, the frequent shot-blockers account for a lot of those blocks. For instance, Mississippi Stateís Jarvis Varnado by himself was responsible for 0.46% of all blocked shots in the game last season. Of the 4,630 players to see action last season, 153 of them accounted for a quarter of D-Iís blocked shots. (By contrast, it took 315 players to account for a quarter of all offensive boards.)
Towards the end of the season, as Pitt was battling UNC for top honors in offensive efficiency-Ėa battle the Panthers would concede with a slump in March--I couldnít help but wonder about the value of Blairís amazing season on the boards. It had to be extremely liberating for Blairís teammates. They didnít need to think twice about taking a shot. Over 40 percent of the time it would end up in a teammateís hands. And when Blair was on the floor, he was getting over half his teamís offensive boards, often in a good position to finish.
On those 178 possessions when Blair grabbed a Pitt miss, the Panthers scored 257 points after the offensive rebound. Thatís 1.44 points per possession, which is better than the typical D-I teamís fast break efficiency. Strictly speaking, thatís 257 points (or 7.1 points per game) that Pitt wouldnít have scored without a Blair-created second chance. (More amazingly, Blair scored 191 of those points himselfóthatís 36 percent of all the points he scored during the season. It was almost as effective to pass him the ball off the rim as it was to dish it to him directly.)
We can be a little more precise about this, though. If DeJuan Blair didnít exist, Pitt still would have someone playing center and would have converted some additional points after offensive rebounds. In addition, Blair may have been such a tenacious rebounder that he stole offensive boards from teammates. One way to get a grasp on Blairís overall worth is to compare the Panthersí offensive rebounding rates (and subsequent conversions) with him on and off the floor.
Finding 3: Blair's offensive boards didn't come at the expense of his teammates.
Thereís some anecdotal evidence to assess the Blair effect. Pitt played one game without him, a November 25 contest against Belmont. The Bruins had a pretty good season--they went 20-12 and tied for second in the Atlantic Sun. But they werenít a good defensive rebounding team, ranking 217th nationally against a weak schedule. Even so, Pitt had its worst offensive rebounding game of the season against Belmont, grabbing just 21 percent of the available boards. I must point out that there were only 24 such boards available because Pitt missed so few shots, and thatís a small enough sample for something fluky to happen, but itís at least an interesting coincidence. Fortunately, through official play-by-play data we can determine if it was more than a fluke.
In looking at Pittís offensive rebounding rate as a team with Blair on and off the floor, it doesnít appear he was taking many rebounds from teammates.
Offensive rebound percentage with Blair on/off court
Blair on 46.7
Blair off 35.7
So on the surface it appears Blairís work was mostly additive. When he was on the bench, either Tyrell Biggs or Gary McGhee was often on the floor in his place. Biggs and McGhee each had offensive rebounding percentages ten to 14 points lower than Blairís, which would explain the difference above. Whatís amazing is that if you take away free throws, which are much more difficult for the offense to rebound, Pittís field goal attempts with Blair on the floor were astonishingly close to true 50/50 propositions when it came to which team got the rebound.
Finding 4: Blair's offensive rebounds were of very high quality.
But Blairís impact was not merely that he gave his team more shots per possession.
Offensive rebound efficiency with Blair on/off court
OR poss OR points Points per OR poss
Blair on 315 435 1.38
Blair off 113 140 1.24
Conclusion: Blair's incredible skill improved Pitt's offense significantly.
Now that we know how much an offensive rebound possession was worth with Blair both on and off the floor, we need just one more table to connect all of the dots here and determine how much Blairís offensive rebounding presence was worth over his replacements.
Offensive rebound frequency with Blair on/off court
Total poss OR poss %OR poss
Blair on 1518 315 20.8
Blair off 795 113 14.2
With Blair off the court, an offensive rebound occurred on 14.2 percent of Pittís possessions. With him on the court that number improved by 6.6 percent. We can apply that difference to the 1,518 possessions Blair was in the game and determine that his presence gave Pitt an extra 99 possessions where at least one offensive rebound occurred. Since each of those possessions was worth 1.38 points, the total value of those 99 possessions was 137 points.
In addition, of the 216 offensive rebound possessions that would have occurred anyway whether Blair was in the game or not, his presence improved their rate of return by 0.14 points per possession, or a total of 30 additional points. Thus, the conclusion is that the total value of Blairís offensive rebounding was 167 points.
This methodology is not perfect--itís trying to create a situation that didnít occur, namely Pittís life without DeJuan Blair. But it seems like a reasonable way to estimate the effect of a supernatural offensive rebounder. In this case, Blairís talent was worth 4.6 points per game, or 0.07 points per possession over the entire season.
Without those points, Pittís offense would have ranked on the fringe of the nationís top 20. As it was, the Panthers were exceeded only by North Carolina. Case closed.
Ken Pomeroy is an author of Basketball Prospectus.
You can contact Ken by clicking here or click here to see Ken's other articles.