Wednesday, March 14, 2012

Do you want me to pass it? No! Ball hogs and offensive efficiency

There is a lot of research on individual and team offensive efficiency - this post combines the two concepts to produce a new metric: extra points per shot (EPPS), which is a rough measure of whether a player should shoot more or less, given who his teammates are.

First I calculated each player's points per shot using this formula:
points / (field goal attempts + (free throw attempts * 0.44))
which is similar to Hollinger's true shooting %.

Then I created a similar statistic for each player's team, apart from the points and shots that player was responsible for. The formula is:
(team points - player's points) / (team FGA - player's FGA + (team FTA - player's FTA)*0.44)
Finally I subtracted team points per shot from player points per shot to yield the extra points per shot (EPPS) each player averages, relative to their teammates. I like this measure better than a "pure" measure of offensive efficiency, because it allows for otherwise efficient scorers to shoot more when they have a weak supporting cast, and penalizes ball hogs with efficient teammates.

I graphed the EPPS against the percentage of a team's shots taken by a player for the top 120 players in the league by points scored per game:



The most striking finding is how much of an outlier Tyson Chandler is, which is not surprising given his 69% FG%. Why can't the Knicks create more shots for him? Is his game limited to wide-open dunks?

Steve Nash and Ray Allen also stand out as efficient scorers who should shoot more - is Nash trying to pad his assist stats to the detriment of his team? Would that make him the league's first selfish assister?

Among the league's top 5 scorers, Lebron James, Kevin Love and Kevin Durant stand out for their efficiency. Kobe Bryant is scoring just under his teammate's PPS, evidence of a not-quite-MVP season, but not of substantial ball-hogging.

Russel Westbrook emerges as the surprising ball-hog from this analysis. He scores an above average 1.10 PPS, close to Blake Griffin and slightly better than MVP Derrick Rose. But the rest of his team scores at 1.14 PPS, the highest in the league, thanks to high efficiency and PPG from James Harden (1.31 and 17.2 PPG) and Kevin Durant (1.22 and 27.9). Pass the ball Russel!

Carmelo Anthony was excluded from the ESPN database, but when included, his numbers are almost identical to Russel Westbrook's, and he does not have the excuse of playing for an efficient team. His absolute efficiency, 1.00 PPS is the 24th worst of the top 150 scorers in the league, placing him next to Antawn Jamison (0.99 PPS) and Tyler Hansbrough (1.00), whose coaches are not getting fired.

The overall least efficient shooter: Raymond Felton, who is apparently leading a mutiny against coach McMillan. That's bold when you're shooting 38% from the field, averaging 0.15 points fewer per shot than the rest of your teammates. They can't all be desperation shots with the shot clock about to expire.

5 comments:

  1. There is something else you should look at:
    http://hoopdata.com/teamshotlocs.aspx

    The Lakers are top 5 in FG% at the rim (as you'd expect with Bynum and Gasol). However, they take the second fewest shots there!

    Kobe is taking way too many shots from way too far away. As bad as his 5.0 attempts beyond the arc are at 29%, his 8.0 shots from 16-23 feet connecting at 41% are even worse (as an aside, Nash connects at an incredible 60% from that range, so I too wish he would shoot more).

    It's really hard to argue that Kobe's ball hogging isn't taking away from the Lakers' big men.

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  2. Good nuance Mint.

    Here's another look: http://starsandasterisks.blogspot.com/2012/03/scoring-but-living-up-to-expectations.html. This time focusing only on the league's top scorers. Kobe and Melo emerge as the least efficient (polite way of saying ball hog).

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  3. From WOW comments, you wrote:
    Has anyone posted an analysis like this? I’m new to this…

    Arturo did a series you might be interested in:
    http://arturogalletti.wordpress.com/2011/03/31/whats-the-use/
    http://arturogalletti.wordpress.com/2011/04/01/putting-things-together/
    http://arturogalletti.wordpress.com/2011/04/01/the-usage-poster/
    http://arturogalletti.wordpress.com/2011/04/03/the-payoff/

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  4. I'm not sure if this is a very accurate way to determine whether a player is helping or hurting his team. In some cases, perhaps, but in cases where the person who is taking the most shots has at least one teammate of more who is an effective scorer, I think its skewing the data. If I was a 40% shooter and I took a third of my team's shots, the team's overall FG% would drop in relation to that. If I have one or more players on my team who can score 50% or better, yet I don't try to get them the ball and/or my shooting takes away from their number of shot attempts, its going to hurt the team's overall FG%.

    Take Carmelo Anthony and Tyson Chandler or Kobe and Bynum/Gasol. Tyson Chandler should get the ball as often as feasible, especially considering how poor Carmelo shot last year. The same goes with Bynum and to a lesser extent Gasol. Bynum is probably going to average 22+ points next year with the 76ers. I wouldn't be surprised if it goes as high as 25+. He is the best offensive option by far due to his FG% and the fact that he is a pretty decent FT shooter for a big. He was also the best offensive option for the Lakers last year, yet he was not going to get the number of possessions he rightfully deserved because that would make Kobe the second option again, a role he will not accept, despite how much better the Lakers are when Bynum gets alot of touches.

    Back to the Knicks, there is really no point in keeping the ball out of Tyson Chandler's hands. He has very few Turnovers Per game (1.6 for his career), he shoots a high percentage from the field and his FT shooting has greatly improved in recent years. Plus he deserves to be rewarded for his defensive contributions. Throw the guy a bone, would ya Melo and Stat!

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