Toxophilite

Posted by Ian Levy on March 10, 2011 under Commentary | Read the First Comment

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Ian Levy is the author of Hickory High, a contributor to Indy Cornrows, and a part of The Two Man Game family. He’ll be bringing his intelligent brand of — mostly quantitative — analysis here on a weekly basis. You can follow Ian on Twitter at @HickoryHigh.

The Boston Celtics received plenty of attention earlier this season when their team FG% was sitting above 50%. This focus was certainly deserved; in the last 20 years, only 10 teams have finished a season shooting better than 50% from the field. Only two teams have done so in the last decade. Unfortunately, the Celtics’ shooting has fallen off slightly since that point, and now sits below the threshold at 49.3%. That percentage is impressive even it falls short of a nice, round benchmark, but even Boston’s strong shooting shouldn’t overshadow another remarkable shooting performance by the Dallas Mavericks.

The Mavericks are second in the NBA — trailing only the Celtics — with a FG% of 47.6%. That puts Dallas 1.7 percentage points behind Boston. If we look at eFG%, which factors in the extra point scored on a three-pointer, the gap between the two teams closes to just 0.2 percentage points. The thing that separates the two teams (and ultimately puts Dallas in front) is the difficulty of their shots.

Hoopdata calculates a field goal percentage measure called “expected field goal percentage,” or XeFG%. Shots from different locations have different difficulties: the league average FG% on a shot at the rim this season is 64.0%, the average FG% on shots from 16-23ft. is 39.5%, etc. XeFG% uses the league average FG% from each shot location and a team’s own average shot selection to calculate the field goal percentage the team would be expected to shoot. My own work on Expected Scoring at Hickory-High is an extension of this idea.

For example, the Charlotte Bobcats have an eFG% of 47.86% this season. The Minnesota Timberwolves have an eFG% of 48.00%. Only 0.14 of a percent separate the two. However, Charlotte’s XeFG% is 50.8%, two full percentage points higher than Minnesota’s 48.8%. Charlotte’s XeFG% is much higher than Minnesota’s because they take 10% more of their shots at the rim then Minnesota does. Although their eFG% is almost the same, looking at the XeFG% shows us that Charlotte is having a much worse shooting season than Minnesota because they are taking easier shots and should therefore be making more of them.

Hoopdata also expresses this idea of “more or less than they should” by calculating a simple ratio, eFG% divided by XeFG%. Here’s where we return to Dallas. When we look at this Offensive Ratio (eFG%/XeFG%) the Mavericks are leading the league at 1.07, Boston’s ratio is 1.05. Hoopdata has this same statistic available for the previous four seasons and over that stretch I could only find four other teams with an Offensive Ratio of 1.07 or higher. I’ll give you hint: It was the same team each season and they play within a four-hour drive of the Grand Canyon. If you guessed the Portland Trailblazers then you need to look at a map.

The thing I found most interesting is how Dallas has been able to accomplish this elite shooting performance on an very different shot distribution from the Phoenix Suns. The table below shows the percentage of each team’s shots which came from each location.

TeamSeason% At the Rim% <10ft.% 10-15ft.% 16-23ft.% 3PTXeFG%eFG%Offensive Ratio
Phoenix2006-200731.3%8.8%8.0%23.3%28.7%50.7%55.15%1.09
Phoenix2007-200831.0%10.0%8.5%24.2%26.0%50.3%55.13%1.10
Phoenix2008-200936.7%13.8%8.3%19.4%21.6%51.0%54.51%1.07
Phoenix2009-201031.7%11.2%8.6%22.4%26.1%50.4%54.57%1.08
Dallas2010-201125.4%13.0%10.9%23.6%27.0%49.4%52.59%1.07

The Phoenix Suns made this list each season by making a ton of the shots everyone expects to make: three-pointers and layups. Dallas has made this list with an incredible shooting performance on mid-range jumpers. 47.5% of the Mavericks’ shots this season are coming from the space between 3ft. and 23ft. away from the basket. The closest Phoenix came to that was in 2007-2008 when 42.7% of their shots were neither at the rim or from behind the three-point line.

When you think of the Mavericks excelling in the mid-range game, Dirk Nowitzki quickly comes to mind. Although he’s an exceptional mid-range shooter, he doesn’t deserve all the credit for the team’s shooting performance this season.

  • Rodrigue Beaubois, Ian Mahinmi, Peja Stojakavic, Dirk Nowitzki and Shawn Marion are all shooting better than the league average on shots from 3-9ft.
  • Dirk Nowitzki, J.J. Barea, Jason Terry, Ian Mahinmi, Rodrigue Beaubois and Tyson Chandler are all shooting better than the league average on shots from 10-15ft.
  • Dirk Nowitzki, Peja Stojakavic, DeShawn Stevenson, Tyson Chandler, Jason Terry, Dominique Jones and Ian Mahinmi are all shooting better than the league average on shots from 16-23ft. Sasha Pavlovic and Caron Butler were also above the league average before they left the Mavericks due to ineptitude and injury respectively.

Altogether the Mavericks attempt 39.1 shots per game from that 3-23ft. space. 28.5, or 72.9% of them are coming from players who are above average shooters from that location. The quantity of players who are shooting well is striking but so is the variety. The list of names above includes players who fill significant minutes at all five positions. The ability to have nearly anyone on the floor knock down a mid-range jumper gives the Mavericks a tremendous amount of offensive flexibility.

I usually make an effort to abstain from unsupportable hyperbole, but I can’t help myself. This may be one of the best jump-shooting teams in history. 17 of the top 40 players in NBA history in terms of three-point field goals made are still active. Jason Williams, Baron Davis and Jamal Crawford all make the list, which takes some of the shine off this discussion. Still, 4 of those 17 who are still active play for the Dallas Mavericks, including three of the top 10. As I mentioned Hoopdata, only has shot location numbers available for the last few seasons so it’s tough to make a statistical argument on the mid-range abilities of teams predating that cut-off. Regardless, the numbers tell me the Mavericks have shooters everywhere and my eyes tell me those shots are going in like never before.