Which Teams are Due For Regression on Defense?

Dec 6, 2014; Houston, TX, USA; Houston Rockets guard James Harden (13) and guard Patrick Beverley (2) after a play during the second quarter against the Phoenix Suns at Toyota Center. Mandatory Credit: Troy Taormina-USA TODAY Sports

With the release of the amazing new SportVU data, we can look at which teams are getting LUCKY. Earlier in the year, I developed a method to look at which players were getting lucky at defending the three. I’ll apply that same method here but look at each location.

How is LUCKY calculated? It’s fairly simple. We find the number of points scored on open shots[1. Open shots are defined as either Open or Wide Open. Exact definitions are found on NBA.com.] at each location (Restricted Area, 3-5 feet, Midrange and Threes) and then find the number of expected points scored on open shots at each location (this is just Open FGA*league average FG%*point value)[2. I’m using population averages here so this will include data for both 2013-14 and the current year.], add up all the points for both the actual points and expected points and then subtract the expected points from the actual points to see the difference. We can also compare each teams’ actual Points Per Shot with the team’s Expected Points Per Shot by adding the difference into the team’s total points allowed and then dividing by FGAs.

Sow how LUCKY have teams been?

Both Houston and OKC lead the league in LUCKY. Both teams have been particularly lucky when it comes to teams missing open jumpers versus them. In fact, both teams have added almost 100 points in missed open jump shots to their defensive efficiency. So what would their defensive efficiency look like if we adjusted for the fact that teams are missing a lot of open shots against them? We can look at Expected Points Allowed Per Shot [3. (Total Points allowed – LUCKY) / FGA] to find out.

The Rockets drop from 2nd in Points Allowed per Shot to 8th in Expected Points Allowed per Shot while the Thunder drop from 5th to 24th, which is quite the drop. Fortunately, the recent additions of Kevin Durant and Westbrook should help offset any potential defensive regression for the Thunder. Meanwhile, expect that Dallas defense to improve (26th in PPS to 16th XPPS), which should scare the rest of the league considering their historically great offense.