Explaining the Bulls' Success Through the Numbers. Part III: What makes our defense tick?

[slowmotion]

An article I wrote x-posted on Blog-a-Bull:

The Bulls defense is predicated on giving up contested long 2s. The thinking goes that if every team has to give something up on defense, it might as well be the most inefficient shot in basketball.

However, many fans have expressed concern that this actually weakens our defense, because we give up too many easy midrange jumpers. Do the numbers support this complaint?

First, let's confirm that the Bulls defense this year is giving up the long 2 by looking at our opponents' distribution of FG attempts.

We lead the league in the percentage of our opponents FG attempts that come from 2pt FGs:



As a corollary to this, we are also leading the league in preventing opponents from shooting 3s:



Where are our opponents' 2pt FG attempts coming from? You guessed it, they're all long 2s. The Bulls are leading the league by a wide margin in the percentage of their opponents shots that are long 2s:





Now that we have confirmed that this is what the Bulls are trying to get their opponents to do, is it a good strategy?

Teams are shooting the midrange 2 against us at just below league average (rank 18), but fans' intuition is correct that teams shoot the long 2 relatively well against us (rank 7):





Since we are mediocre at defending long 2s and we allow teams the opportunity to shoot it at will, does that mean our opponents should go for it? In a word, no:

The long 2 is fool's gold for opposing teams. We give it up whenever they want it and even though we don't defend it particularly well, it's such an inefficient shot that it still allows us to hold opponents to the 2nd lowest FG% overall on 2s.



We supplement this by being the fiercest defenders close to the basket. We are leading the league in blocks, but more importantly we are leading the league in opponents' FG% at the rim:



We also are leading the league in taking away the corner 3:



Remember that the most efficient shots in basketball are dunks, layups, free throws, and corner 3s. These are all areas that the Bulls' defense limits. All of this adds up to having the 3rd best defensive eFG% in the league:



Not bad Bulls.

So remember that when you see teams scorching us on long 2s, there's a method to the madness.

The Bulls defense is very theoretical. Thibs employs game theory to bait opposing teams into taking long jumpers. When players sink jumpers at what seems like a reasonable rate, they take the bait and begin to settle for inefficient shots.



Employing a theoretical approach to team defense is what has allowed poor individual defenders like Carlos Boozer to post career defensive ratings (Boozer's defensive rating was a career best (99, 95, 100, 98) with the Bulls, and ballooned (110) after signing with the Lakers).

In short, Thibs' defensive philosophy is rather genius and maximizes the defensive contributions of everyone on the team. The eye test suggests that we are giving up too many jumpshots, but a deeper analysis of the numbers shows that the team is doing just fine.

[DannyNoonan1221]

How in the hell are we leading in all of those categories and not winning more? That is absurd. But exactly what Thibs wants. It does give me hope for the playoffs.

[slowmotion]

Well, I think the Bulls' players will get better and better at executing this defensive strategy over time.

The system is really what is making our numbers so good. I don't think the players are doing as good of a job as they can. Rose has made comments about how they're still having too many lapses, their communication is bad, and they're giving up too many easy baskets.

As the players learn the system better, our opponent eFG% will go down even more.

The key here is continuity; we have six new players on the roster this year and all are learning Thibs' defensive system for the first time. You can see that this is a problem from the incumbent players' comments about lack of communication on defense.

As our defense improves, we'll win more games. Remember in Thibs' first year in 2010 when no one knew how to play the defense, our record at this point was only three (two) games better than our record now (32-14 v 29-17, but we should be 30-16 had Kirk not single-handedly lost us the first Dallas game), and we finished with the best record in the NBA once our team learned Thibs' style D.

[siriusjames]

Good read, though I think you should also note that 24.6% of opponent field goal attempts are layups against us, 3rd most in the league and we are only 17th in the league defending from 0-3 feet, which can explain our mediocrity in defense, maybe not in theory but in practice.

[Keller61]

We are also 5th best in opponents' FT/FGA, so we're doing well at keeping opponents off the line (best in that category is Cleveland, hmm... ). It appears that our defensive issues are almost entirely due to rebounding (19th in DRB%) and not getting turnovers (29th in opponent TOV%); i.e. we're not hustling after loose balls. In those categories last year, we were 11th and 15th, respectively.

Maybe the fact that we are allowing the lowest FG% at the rim is kind of misleading, since we are giving up so many 2nd chance opportunities at the rim.

[TankOverlord]

Great job OP. Most coaches are woefully ignorant regarding even basic odds and statistics, much to the detriment of their teams. This is slowly starting to change. You can see it in the huge increase of 3PA's the last few years. Props to Thibs for realizing how much the stats matter and how to incorporate it into the X's and O's.

Same thing happened in poker when the online guys took over. Most of the live players were in left field since they hadn't played enough hands to assemble an adequate sample. Nor had they studied the math. A few retooled their games and survived. Unfortunately this takes much longer in sports/politics as it's a closed fraternity with loads of nepotism.

[maynardo]

Thibs and D'Antony changed the League, most teams play heavy pick and roll offense and shoot a ton of 3s based on D'Antony's offense and most teams play Thibs no middle / sagging big man on pick n' roll defense to pack the paint and allow long 2s.

I think what the Warriors do is the greatest example, they Ron Adams in charge of the defense playing the No middle thing but with a lot of switching due to personell and they have Alvin Gentry running a 4out offense D'antony style. They're great in both sides of the floor and that's why they're the best team in the league

[Gmoney3]

Good read, though I think you should also note that 24.6% of opponent field goal attempts are layups against us, 3rd most in the league and we are only 17th in the league defending from 0-3 feet, which can explain our mediocrity in defense, maybe not in theory but in practice.

Is it safe to assume what many have been preaching that a healthy Noah or even a Noah that we can get to 80% of what he was would return us to an elite defense by improving our D against layups and defending the rim from 0-3ft?

[JeremyB0001]

29th in opponent TOV%

I think that this is the most important observation in this thread.

[Rerisen]

29th in opponent TOV%

I think that this is the most important observation in this thread.

It's no surprise though. People been saying this team is old and unathletic, and that is a byproduct of this reality.

We have to play perfect fundamental and set team defense, because outside of Butler hitting some passing lanes, we don't have the swarming length, or speed and agility (like Miami used to have) to force a lot of turnovers.

This hurts in # of attempts teams can put up against us as well as makes us not very good at guarding opponents in transition nor early offense, where teams have hurt us badly trying to score early in the clock before we have everyone in the right place or actively attentive yet to all our rotations and positioning.

Our stop percentages are thus misleading, when you look and see we are still middle of the pack in giving up paints in the point and in transition.

[slowmotion]

I think the lack of forced turnovers is by design. The Bulls never gamble and prioritize getting stops above everything else. I go over the numbers on this in part II of my analyses

[kodo]

It's a nice explanation of the Thib's theory OP.

However, what matters isn't %, but raw points. Total points still win games, not %s and Thibs is playing the % game.

By this I mean any defense that is dead last in the league in opponent 2 pointers made is not a good defense, regardless of percentages.



30th in opponent 2 pointer shots attempted.
30th in opponent 2 pointer shots made.

That's the killer. 2 point shots are the vast majority of shots taken in an NBA game, and to be dead last in that category guarantees a middling defense. Our defense at the rim & 3 pointers, while conceding everything in between, has netted us a meh 12th in overall defensive rating.

However I think Thibs has already adjusted. Starting with the SAS game I saw weakside defenders rotating over on the roll man on P&Rs, something we didn't do before because we concede the 2.

[johnnyvann840]

I think what the Warriors do is the greatest example, they Ron Adams in charge of the defense playing the No middle thing but with a lot of switching due to personell and they have Alvin Gentry running a 4out offense D'antony style. They're great in both sides of the floor and that's why they're the best team in the league

Steve Kerr was a genius getting Gentry and Adams. Gentry spent years with Pringles and knows his offense inside and out. He also knows Doc Rivers system where he was just Associate Head Coach for a year. So, he is inside the head of one of their conference rivals. Then, Kerr goes and gets Ron Adams, who spent time learning the best defensive strategies in the NBA. There is a reason why Steve Kerr always has found himself seemingly in the right place at the right time for around the last 30 years or so. What a story that guy's life is. A pretty amazing man when you look at it.

[JeremyB0001]

29th in opponent TOV%

I think that this is the most important observation in this thread.

It's no surprise though. People been saying this team is old and unathletic, and that is a byproduct of this reality.

We have to play perfect fundamental and set team defense, because outside of Butler hitting some passing lanes, we don't have the swarming length, or speed and agility (like Miami used to have) to force a lot of turnovers.

Eh, maybe it comes as no surprise now, in hindsight. In the pre-season, I heard some people mention that Jo and Taj were hitting their late 20's and wouldn't play like youngins forever. That talk was been greatly amplified now that Jo has a knee injury that's seemingly sapped some of his athleticism and we're losing games. And this is the first I've heard someone said it would cause the team's ability to generate steals to crater, which would be a major blow to the defense. That's to say that hindsight is 20/20. I still think the age thing is overblown when we have Niko (23), Jimmy (25), and Derrick (26) as three main rotation players and Snell (23), McDermott (23), and Moore (25) as possible rotation players. Thibs-coached teams have always de-emphasized the turnover. It's not unclear to me that the Bulls couldn't fix this problem with a schematic adjustment or some increased defensive intensity. It's an incredibly small sample size, but it looked to me like they did that during the Spurs game - multiple defenders were swarming near the player with the ball and it seemed to wreak havoc on the Spurs offense.

[DanTown8587]

29th in opponent TOV%

I think that this is the most important observation in this thread.

I've been saying for two weeks+ that the Bulls problem isn't that they can't defend; rather they simply give up too many extra shots / 100 possessions because teams don't turn the ball over and teams get multiple chances to score.

[mj234eva]

29th in opponent TOV%

I think that this is the most important observation in this thread.

I've been saying for two weeks+ that the Bulls problem isn't that they can't defend; rather they simply give up too many extra shots / 100 possessions because teams don't turn the ball over and teams get multiple chances to score.

viewtopic.php?p=42258797#p42258797

Yea, they're getting "stops" but also giving up too many offensive rebounds, and a good percentage of those possessions still end up being points for the opposing team.

If they generated more turnovers, you're then talking about less shots against, and possibly more "easier" shots for. I say possibly because not all turnovers generated are of the "live" ball variety.