Statophile Volume 20 | The Case For Casey

The Raptors Coaching Options

With all the rumours flying around and a bit of “selective memory” arguments on who should lead the Raptors next season, we thought it was an opportune time to set the record straight. We put together coaching data from several sources as we not only wanted to show historical W-L, but perhaps more importantly metrics like Offensive and Defensive Ratings.

During Bryan Colangelo’s presser on June 1st, he noted he was looking for candidates with “a great deal of experience” and one with a defensive focus. The typical list of potential candidates include: Jeff Van Gundy, Rick Adelman, Lawrence Frank, Dwane Casey, and Maurice Cheeks. I believe that both Van Gundy and Adelman are long shots as I see them only stepping into a situation were the team is poised to make a significant playoff run. So our focus was narrowed to the three most rumoured candidates: Frank, Casey and Cheeks.

I wanted to build a comprehensive picture of their coaching records as certain “pitches” supporting one candidate or another seem to leave out some pretty important data. I also included their records as assistants, even though we do not much too much stock in them.

So what does the data tell us?

All three have quite average overall track records. A 48.3%, a 43.4% and a 49.8% winning percentage won’t get anyone too excited. Average defensive rankings (out of 30 teams, of course) of 14th, 16th and 17th respectively are dead in the middle of the pack. Lawrence Frank has led teams to near the top AND near the bottom in defensive ratings. His offensive ratings have been consistently poor. Dwane Casey’s data as head coach is quite limited. As a head coach, his teams were also quite poor offensively, while teams were he was an assistant performed quite well. Mo Cheeks guided teams more consistently, but was in the middle of the pack most years.

As I argued recently, a coach can certainly make a big difference, but personnel is obviously key. Doc Rivers went from 29.3% winning percentage season (and universal calls to be fired) to a 80.5% winning percentage and a championship trophy the very next year. His team’s defensive rating went from 106.9 in ’06-07 to 98.9 in ’07-08. Did he all the sudden become enlightened with a new defensive scheme? Or perhaps did the Celtics add one of the best defensive of all time to their lineup?
(Note: the playoff data is cut off – click the chart to see it enlarged.)

As I’ve stated, so much depends on the players. But is there a way to measure the impact of coaches given the variance of talent they have worked with over the years?

Regularized Adjusted Plus/Minus (RAPM) for Coaches

Timing is everything: I recently discovered Jeremias Engelmann’s great site (for geeks) “Stats for the NBA“. Mr. Englemann updated (last night in fact) the approximated regularized adjusted +/- (RAPM) numbers [and incredibly simple task ;)] for coaches. For the complete list, click here.

The easiest way to interpret this analysis is this: it attempts to treat the coach as if he is the “6th man” on the court. It’s measuring the coach’s influence on those who play, but as Mr. Englemann highlights “it can’t tell you whether a coach is good at identifying who is good and who is bad, and if he plays the good players more because of that.” For an accessible read of the evolution of plus/minus to RAPM, I recommend this: “A Review of Adjusted Plus/Minus and Stabilization”

With other data being relatively equal, RAPM highlights Casey as a favourite. Almost all of his success differential is at the defensive end as well. Another nice metric: as Dallas’ defensive “coordinator”, the team held league MVP LeBron James to 11 points (on 4 for 15 shooting) in the first five games of the NBA finals.

For the non-statophiles, a Rick Carlisle quote on Casey: “I’m shocked that we still have him here. He’s that good. That situation will be addressed at the right time, but my level of respect for Dwane and what he’s brought our team is extremely high.”

Hire the man.