(Avery Bradley is Still not a Point Guard and an optimistic note on Evan Turner)
Over at the Nylon Calculus, I unveiled a little exploratory analysis I had been dong with SportVu data compariing those stats with offensive efficiency as measured by a stablized plus-minus system for offense called O-RAPM. The SportVu measure that looked like the largest contributor was a measure of passing efficiency that divided the assists, hockey assists and free throw assists by the number of passes the player made, first developed by Nick Neuteufel and Aqeel Phillips.
In that vein, I thought I would increase my research efficiency a little by taking a look at how Passing Efficiency measure applies to the current prospective Celtics line up. Sure, it's August, the NBA is in full off season mode, and the Celtics have a roster that feels likely to change. But, there are no guarantees that it will change significantly. Plus, applying the new measure to a prospective roster helps put it in context and often helps me understand the measure better.
The first thing of note that came out of the analysis for Celtics fans, is that Rajon Rondo is indeed an efficient passer as well as being a ball dominant passer. Rondo rated as the 18th most efficient passer in the league last year but had the highest Passing Impact in the league due to how many passes he threw per 100 possessions, passes per one hundred possessions was also positively correlated to offensive efficiency in the study.
Applying the coefficients from the study to both Passing Efficiency and Passes per Possession, I came up with an estimate of Passing Impact, which is the estimated plus/minus of each player's passing on offense. [1. Measure is calibrated so that every player's Passing Impact is positive outside of turn overs, which was a separate measure in the study]
Below are the three passing measures applied to the Celtics on the current roster other than the incoming rookies and Chris Babb who didn't play enough possessions to be included in the study.
To put some perspective on the numbers here, the Passing Efficiency average of players in the study was .097. In other words, for the average player just under 10% of passes lead to an assist of some kind. The number of passes per player was 71, though that varied greatly by position.
- Not surprising that Rondo and Phil Pressey land in the top spots.
- Evan Turner comes in third, one thing to watch here is that Turner played in the Sixers' very fast paced, if sloppy, offense. There may be some dual causation in the measure with pace, so we'll have to see if he maintains that kind of Passing Efficiency in a new system.
- Avery Bradley IS NOT A POINT GUARD!!!!!!!! He might look like one, he might on the small side and quick, but, no, he is NOT A POINT GUARD!!!!!
- Marcus Thornton had decent efficiency but was an infrequent passer, showing how much he played off of the ball.
- Kelly Olynyk had good Passing Efficiency for his position.
Passing Efficiency, like assists, is highly correlated to position, as is Passing Impact. Here's the table with averages by position:
Using those we can adjust the roster numbers based the level of Passing Efficiency typical of the position, via Basketball Reference, except for Bradley who I changed to a two guard, see above! Any player with a position adjusted rating above one rates as above average for their position, anyone below one is below average for their position:
- Turner comes in as rated the highest over his position of anyone on the prospective roster. If we considered him a two guard, where he played part of his minutes last year, he would still rate as above average. Turner's more traditional distribution metrics assist to turn over ratio only rate him as average, possibly showing the influence of the fast but chaotic Philly offense with the worst turnover rate in the league.
- Olynyk is second in position adjusted passing efficiency, though listed as a center.
- Rondo comes in third in the much tougher point guard spot.
- Bradley, even as a shooting guard has well below average passing efficiency.
- Jared Sullinger is just a bit above average.
There has been some discussion over at Celtics blog on building a roster around a non-shooting point guard as Rondo is reputed to be, and whether or not, in fact, Rondo actually deserves that reputation. I come down on the side that his reputation may be slightly over done, but there's no escaping that he's been a below average shooter from distance and improved mid-range shooting is only a partial salve to the line up spacing problems.
The answer to building around Rondo's shooting, if the Celtics decide to do that, is, of course, to surround him with shooting.
It's a little less clear what the synergies are with passing, and at this point there probably isn't sufficient data to do much with line up analysis, at least using the SportVu measures. That said, my starting assumption is that having additional play making on the court doesn't crowd out the efficacy of the point guard's passing.
At this point, I want to bring in the more traditional assist measurements, in this case assists per 100 possessions and assist to turnover ratio. Both are fairly well correlated to Pass Efficiency, though there may be some diminishing returns for both.
We can also bring in the rookies, Marcus Smart and James Young using their college numbers via Draft Express. Smart had 5.5 assist per 40 minutes pace adjusted, approximately 7.6 per 100 possessions, and an assist/turn over ratio of 1.78. Young had 2.1 assists per 40 minutes, just under 3.0 assists per 100 possessions, and an assist to turnover ratio of .89. I am somewhat more encouraged by Young's good assist numbers than discouraged by his meh asst/tov ratio given his age.
If we look at a possible Zeller-Bass-Green-Bradley-Rondo starting line up, that is four average to below average playmakers on the court with Rondo, with no real secondary play maker. One also would have a fairly lackluster rebounding front court. Even without roster moves, I think that either Sullinger or Olynyk end up getting the starting nod over Bass or Zeller.
The issue with the Celtics roster, as one would expect without real stars, except, perhaps Rondo, is that they don't have any complete offensive players. The shooting guards have limited playmaking skills, the one decent shooting wing, Green, also has limited playmaking abilities. Meanwhile the better playmaking wings aren't shooters. The closest players the Celtics have to complete offensive players are Olynyk or Sullinger, if Sullinger's outside shot starts to fall.
Here's hoping Olynyk, Sullinger or Smart have break out years.