Is LeBron Getting Lucky on Defense?

LeBron is widely regarded as the best wing defender in the NBA. But has he actually been getting lucky on defense over the last two years? Wait, LeBron getting lucky on defense? The man who has inspired a video on his chasedown blocks?

That can’t be right, can it?

Over at Hickory High, Ian Levy calculates Expected Points per Shot (XPPS) based on shot locations. The calculation is simple: multiply each player’s total FGA from each location by the leaguewide expected points per shot at that location, add it up and then divide by the player’s total FGA. Levy then adjusts the total by the number of fouls a player draws using the average value of a pair of free throws (1.511). Then he compares this to the players’ actual points per shot.

Here at Vantage, we can take this metric one step further. Not only do we have shot location data but we have shot defense data as well. Additionally, we even know who is guarding the shooter. So we can calculate a defender’s XPPS. Using this metric, we can see if the defender is getting lucky (or unlucky) with his defense. If the defender is contesting shots and forcing the shooter to take the shot from more difficult shot locations, we’d expect to see a very low XPPS.

Let’s look at LeBron’s defense and see if he has been lucky. Is he forcing his shooters into tough shots? First, we need to calculate the XPPS for the league.

contested shots:

Shot Location  XPPS         fga
a 1.049048 1733
b 1.035159 3214
c 0.971154 2496
d 0.980715 3215
e 1.065789 1748
f 0.923077 26
g 0.777579 1677
h 0.700235 2125
i 0.781012 5119
j 0.719453 2046
k 0.738318 1712
l 1 12
m 0.47619 21
n 0.76643 2252
o 0.769585 868
p 0.783333 840
q 0.760017 2371
r 0.736842 19
s 1.0625 32
t 0.989032 5197
u 1.0197 5127
v 0.967966 4901
w 0.807692 52

(Note: See location chart at the bottom of this post.)

As we can see in the table, some locations have significantly higher XPPS for contested shots than others. We can do this for each type of shot defense.
Now let’s look at LeBron. How has he defended each location?
Location  XPPS           fga
a 1.241379 29
b 0.833333 54
c 1.241379 29
d 1.090909 66
e 1.2 25
g 0.526316 19
h 0.727273 22
i 0.878049 41
j 0.545455 22
k 0.714286 14
n 0.48 25
o 0.857143 14
p 0.571429 14
q 1 18
s 2 1
t 1.125 64
u 1 100
v 0.8 50
w 1 2
Total 0.934319 609

(Note: See location chart at the bottom of this post.)

We can then break this down even further looking at the type of shot defense LeBron has played at each location.
After calculating LeBron’s expected points and actual points for each shot location and type of shot defense (his FGA*points), we add it all up, include expected points on fouls and then divide by total attempts plus missed foul shots. We find that LeBron’s XPPS is 1.01 compared to his actual PPS 0.96.

What does this mean? Our intuition is that LeBron has gotten slightly lucky with his actual points per shot allowed being lower than what you would expect given where and what type of shot defense he played against the opposing player. We suspect the difference isn’t significant enough to say he’s due for any type of regression.

I plan to do a full analysis of all players in the NBA to ground the intuition with data, and to identify the luckiest and unluckiest defenders in the NBA. Stay tuned.

Note: And 1‘s were given an additional 0.755 value to their XPPS since the value of two FT attempts is 1.51. So for 1 FT attempt, the value would be exactly half. As an example, the league had 634 fouled And 1′s in the left low post. Since these shots are always made, their XPPS is going to be 2. However, a free throw attempt follows making the shot, so that is given the value of 0.755 so the XPPS for And 1′s in the left low post would be 2.755.

Leave a Reply

Your email address will not be published. Required fields are marked *