Trainer of the Year?

Posted on June 10, 2008 by


Which team improved the most between 2006-07 and 2007-08?  That’s an easy question.  The Boston Celtics set the all-time record this past season, winning 42 more games than they had the previous year.  Although the Celtics were the first team in league history to improve by more than 40 wins, Doc Rivers – the coach of the team – only finished second in voting for Coach of the Year.  Many NBA observers assumed that the Celtics improvement was more about the additions of Kevin Garnett and Ray Allen, rather than the brilliant coaching of Rivers.

Many of the writers who dismissed the job of Rivers turned to the leader of the team that posted the second biggest leap in 2007-08.  And that team was the New Orleans Hornets.

The Hornets won 39 games in 2006-07 and missed the playoffs.  This past season the Hornets won 56 games, leading the Western Conference for much of the season before finishing just a game behind the LA Lakers.  The top scorers on the Hornets – Chris Paul, David West, Peja Stojakovic, and Tyson Chandler (yes, Chandler was one of four Hornets to average double figures in points) – all played for New Orleans in 2006-07.  Since the key players were all the same, another explanation must be found for this team’s improvement.  And that explanation is the coaching of Byron Scott.

But is this a good explanation?  All four of the top players on the Hornets played more games in 2007-08 than he did in 2006-07.  Paul, Chandler, West, and Stojakovic played in 16, 24, 6, and 64 more games respectively this past season.  So maybe it wasn’t Scott that made the difference.  Maybe it was the team trainer [and/or team doctor(s)].

To settle this question, let’s look at the data. Table One presents what has become the standard two perspectives (standard in this forum) on an NBA team.  First we look at how many wins a team could expect if a player’s per-minute performance didn’t change from the previous season.  Then we look at how many wins we should have seen given what the players actually did this season.  With both perspectives we use the actual minutes the players played in 2007-08.  All that we vary is the per-minute productivity.

Table One: The New Orleans Hornets in 2007-08

Before we get to the question at hand, I should note that the top four scorers on the Hornets were also the top players in Wins Produced.  The order, though, is somewhat different.  Although Chris Paul is truly the most productive player on the team – whether you look at scoring or Wins Produced – the second most productive player is Tyson Chandler, not All-Star David West.  And the ordering of West and Chandler has been the same both in 2006-07 and 2007-08.  In other words, the performance of West and Chandler did not change much across the past two seasons.

The same cannot be said for Stojakovic.  Stojakovic only played 425 minutes in 2006-07 and easily posted a career low in WP48 [Wins Produced per 48 minutes].  In 2007-08 Stojakovic apparently recovered from his injury and his WP48 approached the average mark.  When we compare the two perspectives reported in Table One, we see that the change in Stojakovic’s performance explains a bit more than 40% of the change we see in the team’s fortunes. 

For the remaining change, we turn to the performance of Chris Paul.  Like Stojakovic, Paul also improved last season.  I think, though, that the comparison of 2007-08 to 2006-07 overstates the improvement.  When we compare Paul in 2007-08 to his rookie season (2005-06), we do see progress.  It’s just not quite as big a leap as we see when we compare Paul this season to last (when he was hurt).

Again, as we saw with respect to Stojakovic, injuries appear to have played a role in the performance of Paul.  When we try and correct for that – by using what each player did in 2005-06 – we see very little change in the performance of the Hornets. Specifically, if we just utilize what Paul and Stojakovic did in 2005-06, we see that the Hornets should have expected to win 53.5 wins this past season.

Just to review… given what the Hornets did this year we would expect this team to win 55.1 games.  Given what Stojakovic and Paul did in 2005-06, and what everyone else did in 2006-07 (except as noted in the above table), the Hornets should have won 1.6 fewer games.

And for that improvement, Scott was named Coach of the Year.  And this leads us to today’s question: Who should get an award, the coach or the trainer [and/or doctor(s)] of the Hornets? I think the data suggests the latter.

By the way, for more on why the Hornets were not a surprise this year, please see the following post (offered last March):

The Unsurprising Hornets

– DJ

The WoW Journal Comments Policy

Our research on the NBA was summarized HERE.

The Technical Notes at provides substantially more information on the published research behind Wins Produced and Win Score

Wins Produced, Win Score, and PAWSmin are also discussed in the following posts:

Simple Models of Player Performance

Wins Produced vs. Win Score

What Wins Produced Says and What It Does Not Say

Introducing PAWSmin — and a Defense of Box Score Statistics

Finally, A Guide to Evaluating Models contains useful hints on how to interpret and evaluate statistical models.