Advanced Stat Talk: What XeFG% from the Bulls Game Tells Us About Indy’s Offensive Futility
When is it hot shooting and when is it bad defense?
Overall last night, the Bulls shot 53% from the floor with an eFG% of about 57%. But, as I tweeted last night, I wanted to look at the XeFG% for the teams, because I thought there was a whole lot of settling.
(Explanatory note: XeFG% is short for “expected effective field goal percentage,” which measures the “expected effectiveness of a team’s shot distribution, assuming they shoot league average percentages from every area on the floor.” Basically, different areas of the floor have different levels of effectiveness. For example, dunks/layups are the best to take, corner threes are the second best and midrange jumpers from 16-23 feet are the worst. So if you look at, say, the XeFG% of the Bulls 3PT% last night and see that they shot way better than league average from that distance, they likely either (a) got and made a lot of open threes, or (b) were extra hot from long-range and made a lot of well-contested threes. Also, you can look around on HoopData.com for more fun with XeFG%.)
For the Pacers, it wasn’t all that bad. Their XeFG% was 49.0%, and the league average is 49.5%, so it’s not like they were jacking up an abnormal amount of bad shots (leaving aside the fact that almost all Pacer shots are bad). But they ended up at shooting 46.6% for the game, so they were pretty inaccurate. Every team has bad shooting nights, so this in and of itself isn’t revelatory.
However, last night they weren’t any more inaccurate than usual, unfortunately. Using their YTD numbers, their XeFG% was .469, which will tell you how far below average they are as a shooting team.
Meanwhile, the Bulls took an insane 53% of their shots from 16-23 feet, which is the least effective range. Using league averages, their XeFG% was 45.3%. Using Chicago’s YTD shooting averages, their XeFG% was 41.9%. Meaning they shot about 12 percentage points above the expected league average, and 15 percentage points above what even they would normally do.
So, in a game decided by 9 points, the Pacers submitted their typical shooting performance from the floor on pretty reasonable shot selection, and gave away 4 points to the league average. Meanwhile, Chicago’s shot selection was an opposing coach’s wet dream, but they managed to pick up 21 points against the league average (and 25 against their own standard) simply by hitting shots.
So, is this a function of “Pretty much everybody in the NBA can shoot, so if you give them uncontested jumpers, they’ll hit them,” or “As poorly as the Pacers played, Chicago would lose with that shot selection way more often than they win?” Hard to tell, but probably some of both.
More importantly, it underscores the crucial nature of being able to hit shots.
For all of the “there’s no hustle” and “the team has quit” and “Jim O’Brien is evil” stuff we hear from fans, what’s really making this team bad-to-hopeless instead the marginally mediocre squad that we all expected them to be is painfully simple.
To be a top team, you need to be able to do more than just shoot, but it is next to impossible to even compete if you can’t shoot.
Consider the following chart:
I took all of the teams since 1980, and ranked them based on their eFG%, put them into “rank buckets” where all the Top 5 eFG% teams get Bucket One, the 6th-10th eFG% teams are in Bucket Two, etc. (The earlier years when the NBA had fewer than 30 teams were prorated to match a 30-team rank scale). Then I charted the calculated the combined winning percentage of all the teams in each bucket and plotted them on the graph above.
The 2009-10 Pacers currently rank 26th in the NBA in eFG%, which puts them in the lowest group. Since 1980, there were 140 teams that finished in this “bottom bucket” during this time period, and that collective of poor eFG% shooting teams posted a combined winning percentage of only .315. This is the rough equivalent of 26 wins over an 82-game season. Only 11 (8%) of these teams managed to post a winning record. Meanwhile, 95 (68%) finished with 30 wins or fewer, and 75 (53%) finished with 25 wins or fewer.
A healthy, vintage ’08-09 Danny would help, but not enough to get them to the playoffs. Even before the season, I was afraid that the offense would drop off this year, but I never could have imagined how bad it has become.
Now, granted, even if they could shoot, they still wouldn’t be athletic enough to deal with teams like the Hawks. But if this team could just match last year’s shooting (which wasn’t outlandish with an eFG% of 50.1%, which was just above the league average of 50.0%), they would score 5.2 more PPG. Add in the fact that they’re down from 81% to 76% at the line, and that’s another 1.2 points.
OK … So their shot selection is poor and their XeFG% overall is only about 48.6%. Thus, let’s bring ‘em back to earth and say that it would be more like a total uptick of 4-5 points per game. That doesn’t make them contenders, but it probably gets them closer to .500 — maybe 13-17 or 14-16.
The problem is, what the hell do you do to fix it?
Even if they had better shot selection, that would probably only account for 1/3 of their scoring problem. What do you do when you’re players can’t hit shots (and the opponent knows it)?
Change the offense? Trade for a play-maker? Have more shootarounds? Don’t play players battling injury? Just bite down on the stick and grit it out until 2011?
- The Pacers rank 25th in FG% at the rim, and 22nd in eFG% from beyond the arc. These are the two most important and most productive areas of the floor.
- Tyler Hansbrough shoots only 52.0% at the rim, which is well below the league average of 60.4%. Unfortunately, Mike Dunleavy (51.0%) and Brandon Rush (49.0%) are worse. (So’s McBob, but he’s only had 4 attempts). (Yes…that’s right. If Brandon has a dunk or a layup, it’s less than a 50-50 proposition.)
- The ’09-10 Pacers have improved their defensive efficiency by about 3.5% since last year, which is roughly twice the league-wide improvement. And they’ve improved their defensive eFG% over last season by 3.2%, which is about 3 times the league-wide improvement. Unfortunately, their offensive efficiency in ’09-10 has dropped by a staggering 7.7% — or more than 4 times the league average. This is also more than twice the team’s defensive improvement. The shooting is also predictably worse, and accounts for the bulk of the overall decline in offensive efficiency. Their eFG% got worse by 6.5%, which would be 6 times the league-wide decline.
- As I type this, I’m watching the Pacers fall behind 66-47 to the Griz on at Conseco. The shooting hasn’t been horrible, but dry spells have led to the Memphis spurts. More to the point, it reminds me that I should probably do one of these things on Turnovers. But I’m going to need to get drunk first.