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Vinny Del Negro’s offense

VDN was an elite midrange jumpshooter as a player. With Tim Duncan and David Robinson clogging the lane, VDN kept defenses honest with a career 49.5 eFG% over 12 seasons. But despite his shooting ability, he made just 0.3 threes and 1.3 free throws per game, leaving his career TS% at a mediocre 53.4% . Perhaps he isn’t aware of that last part, because as coach of the Bulls, he’s brought midrange shooting to his offense. Blah.

Hoopdata.com tracks shot selection like NBA HotSpots used to. According to them, NBA teams averaged 40.0 two-point jumpers per 100 possessions last year, accounting for 40.1% of total scoring attempts. The Bulls’ 42.2 and 41.9% ranked 10th and 11th highest respectively. This season, without 3pt shooters Ben Gordon, Andres Nocioni and Larry Hughes, VDN has increased 2pt jumpshots to 50.6 per 100 possessions and 50.5% of scoring attempts, both leading the league.

Chicago media has justified it by saying Vinny is working with what he’s got. It’s true in a way: Luol Deng, Derrick Rose, Brad Miller and Taj Gibson take few 3s or FTs. Vinny tried the three early on, but with the Bulls making just 26.2%, he’s scaled it back to 10.7 attempts over the past six games. The league average is 17.7.

It’s nothing new to argue that an excess of 2pt jumpshots is a bad idea. Just 40.5% of 2pt jumpers shot last year went in, falling well short of the league’s 54.4 TS%. Advanced game charting presents more bad news: 82games says just 7% of all shooting fouls occur on 2pt jumpshots and the Rockets’ Eli Witus says that the 2pt jumpshot is the shot least likely to be offensively rebounded. The data shows that offenses relying heavily on the 2pt shot would be better off penetrating, or even easier, taking a couple steps back to shoot a 3. I want to focus on the jumpshots here, because it’s easier to shift 2pt jumpshots to 3s than to layups.

For the Bulls, there’s little incentive to keep doing what they’re doing. Their shot selection is so bad that even if they shot league average from each location (60.5% inside, 40.1% on 2pt jumpers, 34.7% on 3s), their TS% would be just 51.3%, ranking them 27th in the NBA. Add in their poor shooting, and an ugly 96.9 Offensive Rating results.

But if you’re Del Negro, what can you do? Your team is shooting poorly from 2s, but they’re making just 26.2% 3s. Is there another option?

To try to answer this, I’ll define Percentage of Jumpers as the percentage of your team’s jumpshots that are two-pointers. The league average this year and last was 67%. The Bulls are currently at 80%. What would happen if the Bulls moved to 67%, and the field goal percentages stayed the same?

Using Excel, I ran 100,000 simulations of the following matchup: Team A takes 80 two-pointers and 20 threes each game, and Team B takes 67 two-pointers and 33 threes each game. To start, each 2pt shot has a 39.1% chance of going in, and each 3pt shot has a 26.2% chance of going in – the current rates for the Bulls.

The results:

Conventional wisdom says that taking more 3s at a 26.2% rate is a bad idea. At the very least, the game to game variability would be chaotic. But the math shows differently. Even with a 26.2 3pt%, the Bulls can maintain their winning% by taking more threes, average the same PPG, and barely affect their StDev. With the offensive rebounding increase and the potential for improved floor spacing, this is likely at least a wash scenario for a team in need of a spark offensively.

But the added benefit is, due to practice or simply having more chances to regain their shooting stroke, their 3pt% should improve over time. After all, the lowest team 3pt% in the past five years was 31.2% by the ‘05 Hawks, so 26.2% is probably an anomaly. Here’s how the simulations play out if the Bulls make 29% of threes:

Here we see a distinct advantage in Win% and in PPG. Moving to the 31.2% the lowly Hawks shot a few years back:

The PPG difference of 1.97 per 100 jumpshots translates to about 1.25 per 63 jumpshots, which is the Bulls’ per game average. 55.1% of the time they’d score more points than they would taking 80% 2pt jumpers. Over the course of the season, that shift should add about 3 extra wins.

Personally, I think the Bulls might have better 3pt shooters than the media gives them credit for. Kirk Hinrich and John Salmons both made over 40% last year. Luol Deng leads the league with 8.8 jumpshots per game from 16-23 feet, and makes 38%. Derrick Rose makes 41% of his 6.4 per game, and both their percentages are consistent with last year. If Deng and Rose step back, can they hit 30% of their 3s? It still wouldn’t be efficient, but the numbers say it would improve the Bulls offense. If their shooting more 3s also helps them improve, all the better.