NBA

Evaluating the Offseason Moves of the Houston Rockets

| by David Berri

Shawn Ryan is a 24 year old student currently living in Austin, TX and pursuing dual degrees in Computer Science and Economics. He found the Wages of Wins at a time when he had become newly infatuated with the field of behavioral economics, and it has greatly influenced his educational goals. He has been a fan of basketball from a young age, but has tended to have different favorite teams over time, including the Suns, Cavaliers, Blazers, Hawks, and Rockets among others. He loathes NBA play-by-play commentary, and often has to resort to turning off the sound for the sake of his mental welfare. He is glad to have the opportunity to contribute to this blog, because for some reason, his fiancée tends to fall asleep at unfortunate times while he discusses his very interesting ideas about the NBA with her.

This is part one of a two-part post on the Houston Rockets. In this first part, Shawn will review the various moves the Rockets made in building their 2009-10 roster.  Part two will be a look ahead to the future.

The 2009-10 season was a season of flux for the Houston Rockets. The team’s two most recognizable faces, Yao Ming and Tracy McGrady were non-factors for the Rockets; Yao was sidelined for the entire season, while McGrady played only 46 minutes for the Rockets before being shipped off to New York. Additionally, the Rockets swapped Ron Artest with the Lakers for Trevor Ariza. At the trade deadline, the Rockets entered a complicated 3-team trade with the Sacramento Kings and New York Knicks, the highlights of which are detailed below:

Houston Rockets

to Knicks:      Tracy McGrady

to Kings:        Carl Landry

New York Knicks

to Rockets:    Jordan Hill

Option to swap 2011 1st round picks (top-1 protected)

2012 First Round Pick (top-5 protected)

Sacramento Kings

to Rockets:    Kevin Martin

So did the Rockets come out ahead in these trades? To answer this question, let us first take a look at how many wins all of the players involved in these transactions produced in and out of Houston. Figure One shows the 2009-10 production of the major players involved in the trades mentioned above.

As a point of interest, the players involved in this trade played nearly the same number of minutes in Houston as they did with the various other teams involved in these transactions. But in Houston these players produced more than five additional wins. Most of this difference, though, can be attributed to Carl Landry’s post-trade decline. So the quick snapshot in Figure One might be skewed. That being the case, let’s look at the production of these players over the last three years (see Figure 2). 

From these numbers, we can see that the Rockets again appear to do quite well in these transactions.  Over the last three seasons, the players the Rockets acquired outplayed the players lost when we look at performance per 48 minutes. Furthermore, the players acquired are 5.66 years younger. And finally, the Rockets also acquired two first round draft picks form the Knicks. Unless the Knicks can land LeBron James or Dwyane Wade (while keeping David Lee), it is quite possible these picks from the Knicks will be towards the top of the draft.  And since these are the Knicks, a more likely scenario is the Knicks add Rudy Gay, let David Lee walk, and send very good picks to Houston. 

Beyond these draft picks, the play of Jordan Hill has also been a pleasant surprise. If Hill maintains the level of production that he showed in Houston after the trade (from Fig. 1: Wins Produced per 48 minutes or WP48 of .181 in 384 minutes), then he will be able to largely fill the hole left by Landry’s absence (of course this is dependent on the number of minutes he is given). And while it is more likely that the production over his career will resemble his performance in Houston than New York (i.e. rookies tend to improve over the season) the sample of minutes is on the small side; so it can not be guaranteed that this is what we’ll see in the future.

On the other hand, neither Ariza nor Martin have played as well as expected this season. Martin’s drop-off in production might be attributed to his playing through injuries for the second year in a row. If he is able to re-attain something in the vicinity of the WP48 he achieved in the 2006-07 and 2007-08 seasons (.154 and .182 respectively) then he will be a very welcome addition.

Trevor Ariza, though, doesn’t seem to have the same excuse. In 2008-09, he achieved a career high of 7.58 Wins Produced with aWP48 of .182 (in just under 2000 minutes). This season, he only produced 4.37 wins  with a WP48 of .080 (while having played in excess of 2600 minutes). Fig. 3 compares Ariza’s 2008-09 production with that of 2009-10.

As you can see, Ariza increased his field goal attempts per 48 minutes significantly (by 27.4%) while his shooting efficiency dropped precipitously.

As shown in Fig. 4, Ariza’s shot selection in 2009-10 shifted a great deal in favor of jump shots and away from inside shots. Since Ariza is a below average jump shooter, and a very talented inside finisher, this shift in shot selection was very ill advised. And this change in shot seletion can plausibly be considered cause for his decreased shooting efficiency (though it should be noted that shooting percentages are relatively volatile from year to year, so one should be careful when attributing meaning to changes in shooting percentages, as sheer randomness plays a larger role than most fans, and even NBA “experts” realize).

This increased focus on taking relatively poor shots also coincided with a decrease in steals and rebounds and an increase in turnovers. Consequently, per 48 minute Ariza’s Net Possessions declined 2.94.

Still, Ariza’s points per 48 minutes increased by two, so given the bias of the majority of the NBA’s decision makers to overvalue scoring totals and undervalue stats that increase Net Possessions, it is likely that he has only increased his market value (which was not very high, in spite of his terrific production, at the end of the 2009-10 season). So perhaps there is a market for Ariza’s services.

If a market for Ariza’s services doesn’t emerge, the Rockets would be well served if Coach Rick Adelman and his assistants did their best to influence Ariza to shift back to his prior focus on possessions and efficient shots. If this happens, maybe we’ll see Ariza once again break his single-season wins production record. And perhaps then we’ll see the Rockets back in the playoffs.  In the second part of this article, we will look at that very prospect.

- Shawn Ryan