The NBA's alternate theory raises more questions

To my surprise, NBA's execs argue that pace is a factor in the sudden scoring decline. And a statistics professor weighs in.

Damian Lillard has seen his free throws plummet lately. (Photo by Michael Reaves/Getty Images)

I talked to a professor of statistics about the NBA’s scoring decline. I’ll get to that in a bit. But first, let me present a hypothetical.

Let’s say Damian Lillard has the ball at the top of the key. He sees an opening! He drives to the basket! He draws contact and fires up a layup!

Annnnd… Let’s pause here.

I want to outline a couple choose-your-own adventure scenarios.

Scenario A: A referee sees the contact on Lillard, calls a foul and he goes to the free throw line. This is a big win for him and the Milwaukee Bucks. He’s an AWESOME free-throw shooter, the best in the league at 92.6 percent. Typically he makes both free throws and the possession ends. Other team gets the ball. New possession.

Scenario B: The referees don’t call the foul and the physicality is rewarded with a “play on.” The possession continues! With no whistle, the ball bounces off the rim and importantly, the Bucks can get the offensive rebound and extend the possession. The Bucks recover Lillard’s misses in the paint 27 percent of the time, per Second Spectrum tracking. Instead, the possession goes on and the Bucks grab the board. In that case, the shot clock is reset to 14 and the opposing team has to wait awhile to get the ball back. The possession continues.

I bring up this example because ESPN writer Zach Lowe was joined by league office executives Joe Dumars and Monty McCutchen on his podcast The Lowe Post last Friday. Lowe got them, on the record, to discuss the drastic downturn in scoring and the role of officiating at the heart of it. I listened with an open mind. Maybe I missed something in my statistical analysis that reported a dramatic drop in foul calls — just about all whistles, really — since around Feb 1. All of the signs say the league’s officiating is responsible for the drop.

As I listened to Dumars and McCutchen’s responses to Lowe’s questions, plays like the Lillard one above were dancing in my head.

Stepping back for a moment, this story escalated quickly. To recap:

• March 1: I posted “NBA scoring is crashing. Why?” noting a significant drop in scoring across the league, with signs pointing to fewer foul calls.

• March 8-12: The Knicks hold opponents to <80 three games in a row. The story becomes louder.

• March 12: Marc Stein hears straight from the league office that there was no directive from to referees about lowering foul calls.

• March 12: NBA competition committee meets.

• March 13: Shams Charania reports NBA competition committee “discussed ways to incorporate more defensive freedom … using the next few months to strategize.”

• March 14: I posted “The NBA’s bizarre free-throw drought continues” analysis

• March 14: Ethan Strauss posts his interview with me on House of Strauss.

• March 15: Lowe interviews Dumars and McCutchen on The Lowe Post. Dumars and McCutchen deny there was a directive.

• March 15: Later that night, Adrian Wojnarowski reports that the NBA told teams on Tuesday that “officiating focus” helped lead to scoring decline.

• March 18: Stein gets a copy of the memo and confirms that the league believes officiating played a role.

OK, got all that? Just wanted to get you up to speed. A lot has happened.

I bring up the Lillard example up at the top because it cuts to the heart of the issue. Something that McCutchen said to Lowe on the Lowe Post, in reference to the large drop in scoring, made me think of it.

McCutchen acknowledged that officiating played a role in the decline, but that wasn’t all of it. “I also think it’s important to say,” McCutchen said, “that it’s easy for outside influences — media, fans, wherever it may be, teams in some instances — to focus on one area as the thing.”

I think he was referring to referees calling fewer fouls here.

McCutchen continued and suggested an alternate explanation for the scoring dip.

“You know,” McCutchen said, “possessions are down right now, which accounts for about 40 percent of that drop.”

From the NBA’s perspective, pace is clearly an important piece to this puzzle. Stein’s copy of the memo to teams shows that the league believes “slower pace” played a role in the scoring drop, mentioning it first in line.

“Slower pace, style of play, competitive intensity, officiating focus, etc.. have all been contributing factors identified thus far."

And then on the Lowe Post, we hear McCutchen reiterating that factor, noting that possessions are down.

I was surprised that the league would use this argument. Because, to me, possessions being down is a direct result of referees swallowing their whistle on potential foul plays. Let me explain.

So in Scenario A, the referees call the foul. Scenario B, they don’t.

Which possession is going to last longer? I think it’s pretty clearly B. The play goes on. The clock keeps running. The possession doesn’t end.

I’ve got some numbers for you. Possessions with a 2-point miss are on average 3.4 seconds longer than ones with a shooting foul called by officials.

Per Second Spectrum tracking, here’s the average possession length of a variety of outcomes this season:

And you know what? This makes sense. Free throws artificially cut possessions early, which means that the more you call fouls, possession counts begin to pile up. (While a free-throw miss technically could result in an offensive rebound, it almost never happens.)

Another big impact: foul calls have a multiplier effect thanks to the bonus. In the NBA, teams enter the bonus on the fifth foul. The more times that a foul is called, the quicker that teams get into the bonus. In a penalty situation, every non-shooting foul results in free throws, too. More free throws! As you can see above, a possession that ends with a foul in the bonus is the shortest of these scenarios: 9.9 seconds on average. (Some of these lengths may be slightly impacted by end-of-game desperation fouls but the point remains.)

So the quicker that teams get into the bonus, the quicker the possessions, the higher the possession count! So when the refs were calling fouls a lot, it makes perfect sense that possessions were up, too. When they weren’t calling fouls, the possessions dropped in number.

I also used Lillard as an example up top because of some whip-smart research from Sravan (@SravanNBA) who gave us the following graphic inside his fascinating writeup. Lillard has been the biggest victim of the officiating change, at least by free throw attempts:

via @SravanNBA

Lillard has seen his free throw attempts sliced nearly in half (the Bucks’ free throws are down too). And sure enough, when you look at the Bucks’ possession counts, you notice that they are down about 5 possessions per game, from about 102 to 97 in those two stretches.

It seems pretty clear to me that possessions are down because free throws are down.

The box score data proves this as well. The more free throws in a game, the more possessions there tends to be. For illustration purposes, I pulled up every game this season. Let’s keep it simple and focus on the games with the most and least free throws to see if possession counts are impacted (I’m excluding overtimes).

The 10 games with the highest number of free throws yielded an average of 102.4 possessions. The 10 games with the fewest number of free throws?

95.3 possessions.

A difference of 7.1 possessions.

That’s a lot.

Again, more fouls = more possessions. Fewer fouls = fewer possessions.

You can also see this effect visually too. Here’s the the trendline for free throws vs. possessions for every game this season. The trendline is in the upward direction (a positive relationship), which tells us that an increase in free throws is associated with an increase in the number of possessions. And a decrease in free throws tends to see a decrease in the number of possessions.

So when possessions are down, we shouldn’t interpret that as a cause of the scoring decline. From where I sit, it’s much more persuasive that it’s actually a result of the softer whistle.

Knowing this, if you’re trying to persuade the public that the scoring decline wasn’t because of officiating changes, why bring up the possession count at all?

The battle of semantics

After listening to Dumars and McCutchen’s responses, I’m more convinced that something happened. For one, it was confusing to hear Dumars argue that the NBA doesn’t want lower scores and then launch into an anecdote about how he went to an awesome low-scoring game between Boston and Denver. Putting that aside.

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McCutchen spent some time saying the scoring decline wasn’t the result of a directive about swallowing the whistle (my words), but rather some coaching that may have led to a scoring decline. There was emphasis on consistency not a decree.

Look, it’s gotten bogged down in a battle of semantics. Was it a directive, a change or … coaching? The league is pretty adamant that it was not a directive. Fine. But I think the further we go along, dwelling on that strikes me as a bit of a straw man. As Lowe suggested on the pod, it doesn’t have to be a memo or something written in blood.

Let’s say the speed limit on Main Street is posted at 35 miles per hour. Signs are posted everywhere, but everyone’s driving 45 and doing so safely. Accidents aren’t piling up. Traffic is light. The police are there monitoring, but not pulling people over, even for going 45. Everyone is just going about their business as usual.

Imagine, then, all of sudden, for a week straight, the police are pulling people over the moment the speed gun ticks above 35. Boom, boom, boom. Everyone’s getting tickets for driving 36 and 39 miles per hour.

That would be shock, right? What caused THAT, people would wonder? Maybe there was a memo. It could have just come from something the police chief said off-hand in a meeting, maybe a reminder about promotions at the end of the year or something soft like that. Or maybe the police chief congratulates an officer in front of the group for handing out some tickets for cars speeding at 37 on Main St.

Now, was it a directive? Probably not. They were just emphasizing the speed limit. It was coaching.

To me, it’s pretty clear something happened off the court. After listening to the Lowe Post (Zach does an amazing job on that podcast and everywhere, by the way) and hearing the unsatisfying explanations, I’ve grown only more confident in that position.

But it really sealed things once I talked to Dr. Sam Cook.

Statistician: The scoring decline almost certainly was not random

I hadn’t run a specific statistical analysis to see if the scoring decline was statistically significant or whether this was something that was just random. There are some who believe that this is much ado about nothing … that we are seeing patterns among the coin flips that aren’t actually there.

So I had an idea. Why don’t I get a professional to see if this was statistically significant?

I reached out to Cook on Tuesday and he got back to me with the analysis on Friday morning. So I had this in my inbox when The Lowe Post was posted.

To be clear, I took statistics in college, but I wanted a professional to way in. So I reached out to Cook, a professor of statistics at Boston University. His official bio: “A clinical associate professor of math education at Boston University Wheelock College of Education & Human Development, with an affiliation in the College of Arts & Sciences Mathematics and Statistics.” Sam has helped me out with the high-level stats stuff before (you can follow him at @StatsSam on X or Bluesky).

I sent a spreadsheet his way. I gave him a game log for every team with their line of box-score statistics this season and asked him if the downturn in scoring after the All-Star break is statistically significant. That is, could the scoring decline be explained purely by random variation? What’s the chance that this is just random?

He looked at the distribution of three stats: A) points B) free throws C) fouls in the games before the All-Star break and compared them to the games after the All-Star break.

He ran the analysis.

And it was pretty clear.

Cook’s verdict:

“The likelihood of the post-All-Star-Break coming from the same distribution as the pre All-Star-break numbers is very near 0 (depending on the stat, between 1 in a billion and 1 in a trillion).

Safe to say, it’s a very low chance that this is just randomness. Basically, we’re looking at two different seasons. When Stephen Curry scored 60 on February 3, it was the 15th 50-plus scoring night of the season. We haven’t seen one since. Something is different.

So, when precisely did the split happen?

It’s hard to say.

But Cook went ahead and ran the numbers for Jan 29 split instead of All-Star Break (mid-February). That was the Monday after the scoring blitz from Luka Doncic 73 (Friday) and Joel Embiid’s 70 (the Monday before). In my initial post, I found that the scoring peak happened a couple weeks before ASB, so it made sense to look at that dividing point in the two distributions as well.

So, moving the line to the Monday after Luka’s scoring, did that change the results?

Cook found the same thing: almost zero chance that this was random.

Cook wrote to me that “random chance explaining fouls and free throws was in a 1-in-a-billion range. Points scored was a little more possible but still about 1-in-10-million.”

That’s a lot of zeros. I asked him what he made of the data.

“What this tells me is that the way games are progressing is significantly different, something has changed.”

I asked him to consider the point that Tom Ziller made about injuries. Ziller pointed out that the free-throw/scoring drop coincided with injuries to top foul-hunters Joel Embiid and Trae Young. FromGood Morning It's Basketball:

You know who led the league in free throws per game by no small margin through the end of January? Joel Embiid. And you know who hasn’t played a single game since the beginning of February? Joel Embiid. It’s not just Joel: Trae Young was No. 5 in free throws per game through January, and has played only nine games since due to injury.

You should read Ziller’s full post and this week’s hit. It’s full of really interesting thoughts about the issue, though I can’t say I agree with all of it. The Embiid/Trae angle was something I hadn’t seriously considered until Ziller brought it up. So Cook removed the Sixers and the Hawks from the sample. Cook’s verdict: still can’t be explained by pure randomness.

Cook adjusted for overtimes. he adjusted for pace. It kept coming up the same takeaway: something happened. The difference is statistically significant. Cook’s wrote me his final conclusion:

“Obviously, this analysis cannot identify mindset or the like, but what it can do is pretty definitively identify that PTS, PF, and FTA have significantly changed and the reasonable explanations cited above do little to explain the change, thus I am confident there is a different factor or factors contributing to the change.

All were significantly different, with close to 0% chance of the difference being caused by random variation.”

Well, then.

Like I said on Strauss’ pod last week, I like the product! The games are ending sooner, which is a big win for this East Coaster. When it comes to any officiating influences, I’m with Lowe on this one. It doesn’t have to be a memo or an official directive. It could come in the form of certain plays being shown to officials or a public praising of a certain ruling on a play. That makes more sense to me.

We’ll see what happens going forward. Teams are closely monitoring the officiating trends. The Lillard play will be scrutinized more than ever. We’re a month away before the postseason begins and the impact of every whistle gets louder and louder. For now, though, the play goes on.