Shot Distance, Offensive Efficiency, & Wins

Andre Khatchaturian —  August 1, 2013

This year in the NBA, there were over 201,000 field goals attempted from a wide variety of distances on the court. The quality of all of those shots taken was dependent on several factors such as whether the shot was contested or not, the type of play ran by the coach, the time remaining on the shot clock, and of course the distance of the shot.

Shot distance turns out to be an extremely important indicator whether a shot will be successful or not. The table below illustrates the expected values of shots from different ranges based on the league average from those distances:

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Shots in the interior (within 8 feet from the rim) are most successful at 55.3%, giving those shots an expected value of 1.11 points. The percentages sharply decline the farther we get from the hoop as the field goal percentage for mid-range jumpers falls below 40 percent. When we go beyond the arc, the percentage dips to 36%. However, since threes have a point value of three, the expected value for threes is 1.08 points per shot, making it a fairly efficient shot.

With this line of logic, one may believe that teams that take the most shots from within eight feet and from three-point land would be the most successful because they are taking higher quality shots. It turns that this isn’t exactly the case, though.

After running a regression between the distribution of shots from each distance range with intervals of 8 feet (less than 8 feet, 8-16 feet, 16-24 feet, and greater than 24 feet) with wins, a weak correlation was found and no specific distance range was statistically significant. In other words, just because teams took more efficient shots, it didn’t necessarily help them win more games.

The Lakers are a great example. 72.7% of all Lakers shots came from three point land or from within eight feet. This was the fourth highest percentage in the league behind the Rockets, Nuggets, and Pistons. With Dwight Howard in the middle (he took the second most shot attempts from <8 feet) and Metta World Peace jacking up threes night and day (16th in the NBA in three point attempts), it’s no surprise that the Lakers are high on top of this list. They definitely took plenty of quality shots in terms of shot distance, but only managed to win 45 games.

The problem? The Lakers only made 47.5% of their shots from those two distance ranges – 18th best in the league. It turns out that success isn’t based on how many shots a team takes from these shot ranges, but how efficient they are with those shots. In fact, having variety is good in terms of shot selection. It creates unpredictability. As long as a team makes the important shots from beyond the arc and close to the basket, they will maximize their chances of winning games. That being said, we shouldn’t completely discount shot frequency. Regression analysis between offensive efficiency rating and the frequency of shots from different ranges showed that shots from the efficient ranges were statistically significant. When teams took more quality shots, they had a higher offensive efficiency. There’s a strong positive correlation between OEff Rating with wins so one can say that there is an implied correlation between the frequency of shots taken from efficient ranges with wins.

In terms of a direct (and stronger) correlation, though, FG% from the efficient ranges was all that mattered. In fact, after running a regression between success of shots from various ranges (less than 8 feet, 8-16 feet, 16-24 feet, and 24+ feet) and wins, only the ‘less than 8 feet’ range and ‘24+ feet’ range were statistically significant. This means that success in those ranges (let’s call them the efficient ranges) was correlated with wins.

For instance, 67.3% of Miami’s shots came from the two efficient ranges (12th highest), but they were the most efficient team making 53.3% of their shots from those distances.

Here’s a breakdown. On the left is the list of the ten teams who most frequently took their shots from the efficient ranges. On the right is the success they had in those ranges:

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As you can see on the table to the right, the top nine teams that were most successful from the efficient ranges had at least a .500 record. While we see several teams on both lists, it should be clear that their success was correlated stronger with their success in the efficient ranges rather than the frequency of their shots from those distances. For example, the Rockets may have taken more efficient shots than the Nuggets, but they weren’t as successful, which may be related to why they won 12 fewer games.

What about on the defensive side of the ball? Surely if a team is good at defending shots from the efficient ranges, they will be successful, too, right? The Memphis Grizzlies and Indiana Pacers ranked 24th and 25th, respectively, in terms of field goal percentage from the 0-8 feet and three point land. However, they were both stout defensive teams throughout the season from those distances.

When conducting the same regression for OppFG% in the efficient zones with wins, we see that only shots defended from 0-8 feet were statistically significant. This means that a team’s performance defensively in this range was correlated with wins. Sure enough, from the nine teams with the lowest OppFG% in this range, eight of them made the playoffs. Indiana and Memphis were 1st and 8th, respectively. We also see an extremely strong correlation between the frequency of shots allowed from the efficient zones with defensive efficiency rating. In other words, teams that allowed fewer shots from the efficient zones didn’t necessarily win more games, but they had a lower defensive efficiency rating. There is a strong correlation between defensive efficiency rating with wins, so there is in fact an implied correlation between the frequency of shots allowed from different zones with wins.

The Lakers, despite having Dwight Howard in the paint, were 21st in terms of OppFG% on shots between 0 and 8 feet at 56.4%. This was the third highest percentage among all playoff teams.

Even more interestingly, 42.2% of shots the Lakers faced came from within 0-8 feet – 11th lowest in the league. Without Dwight in the lineup, Orlando faced FEWER shots from within that very range (they were 7th.) One would think having Dwight in the interior would force teams to take farther shots because of his presence, but that wasn’t the case this year with the Lakers.

So did having Dwight in the paint really help the Lakers defensively? It’ll be interesting to see how those numbers change this year.

The Lakers were a middle of the pack team in terms of making and defending efficient shots. As a result, they were a middle of the pack team overall.

The prospects of the Lakers improving these figures are questionable. Adding Jordan Farmar and Nick Young doesn’t really put the Lakers over the top in terms of three-point efficiency. They can shoot the three ball but they’re not amazing.

However, the departure of MWP and a healthy Nash (who is a 42% life time three point threat) will make the Lakers a more efficient three point shooting team (that is if Nick Young doesn’t reprise the role of MWP and jack up crazy threes all season.)

In terms of interior offense, losing Dwight will definitely hurt. He made 60 percent of his shots from within 0-8 feet and this means that Chris Kaman, Pau Gasol and Jordan Hill will really have to step up to fill in his shoes. Kobe has shown that he can still drive in the lane and take quality shots from close range, but there are many question marks surrounding his injury.

Then again, perhaps the unpredictability that will come with not having Howard and World Peace in the lineup will help the Lakers. Let’s face it – the team took many shots from within 0-8 feet and another chunk from beyond the arc. One of the biggest criticisms against the Lakers last year was their spacing and lack of chemistry. If spacing and chemistry don’t exist, shot quality is going to be poor. These are all things that can be fixed with a full training camp and inputting system guys that fit D’Antoni’s style. D’Antoni will have the luxury of having a full training camp and offseason this year and the Lakers front office has definitely acquired numerous players that will probably fit well in D’Antoni’s offense. It will definitely be an interesting aspect of the game to observe in the 2013-14 season.

Finally, it should be crucial to note that there are obviously a variety of other factors that are correlated with a team’s chances of winning a game. Shot distance is only one of them. That being said, the numbers show that shooting and defending well from specific distance ranges effect a team’s chances of winning and the Lakers will have to be more efficient from beyond the arc and from close range if they’re going to shock the basketball world and be a contender in the West.

Andre Khatchaturian