Boston And The Math Apocalypse

Stop guarding the Celtics like other teams

• Teams let Boston off the hook by guarding them traditionally

• It will take a tailored defensive shift to actually beat them four times

• Boston’s real triumph is taking advantage of coach and player stubbornness

With 3:50 to go in the 4th on November 10th, the Milwaukee Bucks had a very real chance to beat the defending champion Boston Celtics. They were at home, trailing by just two. The Bucks in this game shot better from both the field and 3-point range in percentage. They finished with just one more turnover. They got 43-13-5 from Giannis.

And they lost.

The Bucks held the lead at half, and after giving it up in the third quarter, had stayed within one possession almost the entire time to give themselves a chance to win.

Then this possession happened.

Derrick White initiates a pick and roll with Jayson Tatum, which Tatum slips. Lillard shows vs. White and then recovers well. The Celtics have the matchup they want. Or at least, the one they are telling the Bucks they want.

Look at the top right and how close Brook Lopez is to Al Horford. AJ Green is staying with Jrue Holiday. Jaylen Brown is in dunker spot, giving Taurean Prince the ability to at least try and help if Tatum drives.

It’s contained, with one obvious weakness: Tatum is matched up against Lillard.

And Giannis Antetokounmpo can’t help himself from helping Dame. He shows on Tatum to cut off the middle of the floor, believing he can recover. But he can’t.

The Bucks cut this to two on a Green three on the next possession. It’s all Butterfly Effect, but theoretically, that shot would have been for the lead if the Bucks had not given up this three to make it five with 3:40 to go. The Bucks would lose.

Because Giannis had to help.

That’s not to say that it was Giannis’s mistake or the coaching staff's if the game plan had been to crowd Tatum there. It’s the same mistake every team in the league has made for the past two seasons vs. Boston: an inability to understand one simple truth.

You have to guard the Boston Celtics by doing the opposite of what you know.

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THE HAZY SUMMIT OF RESPECT

We’re reaching the crest of the Celtics.

After years of questioning whether they had “the guy” or if a team without a consensus Top-Five player (which Tatum is this season) could win a title, after so many failures, they reached the mountaintop and won the title.

They were the best team last season and had one of the best full seasons we’ve ever seen from a team. They played smart, selflessly, and with the kind of joy that brings titles. And it did.

After winning the title and picking up where they left off last season, the proceeding 20-plus games has seen a fascinating shift in how people talk about Boston. Gone are the doubters and the suggestions that their path last season was particularly weak due to injuries and a favorable Finals opponent.

On the one hand, it’s good that the conversation has shifted, and Boston is getting the credit they deserve not only for what they built but the way they sustained it and stuck with it through so many failures to finally reach the apex. They are 20-5.

On the other…, we’re starting to do what we do in times like these and believe nothing can stop Boston. Even though the last six NBA champions going back to the 2019 Raptors have all been a different team each season, the idea now is that Boston is at least going back-to-back, if not beginning a dynasty.

Given their conference's weakness and Boston’s overall profile, it's hard to argue. And if teams continue to do what they have done in the regular season and defend Boston like any other team, that’s what will happen.

The question is whether any team will figure out that the Celtics’ advantage isn’t their heart, hustle, or even their talent despite a stellar group of what will be multiple Hall-of-Famers in their top seven. It’s the math.

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You know the Celtics shoot a lot of threes. I don’t need to tell you that. You’re aware. They bomb atomically. For every 100 possessions, Boston makes three more threes than the second-best team (the Hornets, coached by former Celtics assistant Charles Lee).

They are 12th in 3-point percentage; this isn’t the Splash Brothers. But they shoot with so much volume, so consistently, that teams absolutely drown trying to keep up.

Creating enough makeable threes isn’t just about hoisting. The Celtics aren’t seven seconds or less. They take them in transition; they take the third most threes per game in transition. But that’s not where they get most of them from.

It’s this.

The Pistons can’t contain on the ball, so Tobias Harris is all the way on the other side of the paint showing help on the drive. Ivey has to close out, Theoretically, Cade would swing over in time to guard White, THJ rotates down to Porzingis, Stewart X’s out to Jrue, and so forth.

But Boston has proven you can’t do this. Their spacing is too perfect, and their reads and understanding of triggers are too good. Cade’s there. But once the shot is up, you’ve lost. This is where every traditional scheme fails: if you surrender a three-pointer to Boston that isn’t off-the-dribble contested, even if they miss, you’ve lost the possession.

The minute Tobias Harris left his man open on the perimeter, the Pistons lost that possession because Boston got what it wanted: someone open on the perimeter.

Here’s another Pistons possession. Look at how many Pistons wind up in the paint on a… ahem, Jrue Holiday-Luke Kornet pick and roll.

Again, the minute Ron Holland moves into the paint to provide extra help on Luke Kornet, the Pistons have lost this possession. Luke Kornet on 2-point attempts with a defender within two feet of him shoots 40%, 0.8 per possession. Peyton Pritchard on catch-and-shoot threes averages 49% and 1.46 points per shot.

THAT’S A 146 OFFENSIVE RATING COMPARED TO A LEAGUE AVERAGE 113.7.

The counter is always that the Jays will kill you in isolation if you don’t help. And they are elite at it. But watch what happens when Georges Niang leaves Al Horford in the dunker spot to help Ty Jerome… who actually had defended the ISO as well as you can!

Do you know what Jaylen Brown averages per possession in isolation on non-three-point attempts this season? 0.87 points per possession. ¹

Congrats, you made sure that Jaylen Brown couldn’t shoot over Ty Jerome despite pretty good defense, and in doing so, you gave up a much higher efficiency shot.

I’m not saying this isn’t difficult; it’s nearly impossible. Tatum torches AJ Green here.
It’s a layup if someone doesn’t help.

Brook Lopez and Giannis Antetokounmpo both help, Lillard and Green both go to Horford, and hey, there’s another wide-open shot for Derrick White. And what’s White’s points per shot on a catch-and-shoot three?

1.4 points per possession. A 140 offensive rating.

Here’s the only way this makes sense with Boston: you have to assume Tatum converts his layup 100% of the time (2.0 points per possession) and that White only hits a catch-and-shoot, in-rhythm, wide-open look at his normal rate of 1.4.

You are not better off with this shot. You have traded a made layup for Tatum (2 points) for a three-pointer for White (3 points). That’s worth it if the probabilities work in your favor, but they quite literally do not.

On drives this season, when he attempts to score, Jayson Tatum is averaging 1.09 points per possession. That’s great! But that’s still below the efficiency on basically any 3-point attempt Boston generates.

The Celtics are Kevin McAllister in this scene, shouting at the defense “I’m gonna score in the paint, morons! Come and get me!”

And there the defenses go, charging up the stairs.

“Oh, no, it’s Luke Kornet on the roll! Better go guard him!”

Luke Kornet is great on the roll! He’s averaging 1.44 points per possession on it this season! On…. let me see here… oh yes, SEVEN ATTEMPTS. Is it crazy to ask Luke Kornet to beat you instead of the Sixth Man of the Year?

The challenge for NBA defenses nightly is trying to limit the opponent to what shots they want to surrender. Mid-range contested pull-ups are the preference. What’s remarkable is that the Celtics have used the traditional concept that you want to defend the rim first and inverted it.

Boston’s not an elite shooting team, despite how it feels watching them or playing against them. They’re 12th in 3-point percentage. They are 5th in eFG%. Good! But they’re not just outshooting teams by percentage. There is cost to their efficiency based on volume, to be sure, but even accounting for that, their efficiency is not insurmountable.

It’s important to clarify that this isn’t just about jacking up threes. Boston doesn’t just launch them, nor should they. They’ve found the limit of their effectiveness.

Whereas the Splash Brother Warriors could honestly forgo shot selection and just chuck them and win that way (though they didn’t most of the time), this Boston team generates constant rhythm spot-up threes, and prevents them at a high rate.

That chart looks at just points off made spot-up threes vs. allowed points off spot-up threes per game. Boston is starting every game with a built-in math advantage because of these numbers. Notice that the gap between Boston and No.2 Phoenix (5.6 points per game) is wider than between Phoenix and the 11th-best team on that chart.

THE MACHINE DOESN’T CARE

Did you know that the Celtics allow the 5th-most points in the paint per 100 possessions this season? Or that they are 8th-worst defending the pick-and-roll ballhandler? The best on-ball scorers in the league go nuts on Boston, and it doesn’t really matter.

Because on those possessions, opponents are still only scoring 0.94 points per possession, while Boston is scoring 1.19 points per possession on catch-and-shoot jumpers.

Every time on average that a ballhandler attempts to score on Boston in pick-and-roll and Boston goes down on the other end and takes a catch-and-shoot three, opponents are losing by 0.25 points per possession. ²

Now, what happens when you actually guard these three-point attempts by stying home? On guarded catch-and-shoot attempts, Boston drops to 1.04 points per possession, a 104 offensive rating.

I’ve thrown a bunch of numbers at you. Let’s go through your options here.

Jayson Tatum driving field goal attempt: 1.09 points per possession

Jayson Tatum dribble jumper: 0.96 points per possession

Jaylen Brown driving field goal attempt: 0.89 points per possession.

Jaylen Brown dribble jumper: 0.95 points per possession

A BOSTON CELTICS CATCH-AND-SHOOT THREE-POINT ATTEMPT: 1.19 points per possession.

Now, I’m not saying this is that simple. The efficiency on those attempts by Tatum and Brown are inherently impacted by the very help I’m advocating against. If you don’t send help, they convert more of them and the efficiency goes up.

But look at those numbers. Tatum has to add 10 points for every 100 possessions he drives to make up that difference.

THE WEIGHT OF THE CART

Then there’s the fatigue factor. Switch hunting slows down the offense and energy for the other five guys but also wears down the ballhandler. Tell Jayson Tatum to drive against any defender, even outmatched ones, for 35 minutes and he’s probably going to be gassed by the end. And let’s be clear: Tatum can win the game that way. But it’s harder.

That’s on top of the fact that Boston thrives with this playstyle. This is the gameplan.

Every time a defender takes a step away from their man on the perimeter, the Celtics expected win percentage goes up. Every time a team tries to double Tatum or Brown, their success rate increases.

The reason this is so difficult isn’t about the math, even though if you tried putting these numbers up in a meeting the players’ eyes would glaze over and they’d tune out for the most part.

It’s that it goes against every instinct and tendency put into players.

“Crowd the ballhandler’s space.”

“Show a crowd.”

“Protect the rim.”

“Help the helper.”

Boston hunts switches constantly and when they get the one they want, the opponent freaks out because their teammate, who they love and care about, is about to get roasted by Jayson Tatum.

But if you want to beat Boston? Shoot the hostage.

It’s pain tolerance. Live with the ISOs and the highlights and normalize the math game.

NO STRATEGY IS PERFECT

You can still lose this way; Tatum and Brown (and White and Holiday and oh, yeah, Porzingis) are good enough to adapt and punish. Boston runs a high amount of post-ups and does so efficiently; they average 1.03 points per possession on those shots. You know what that’s better than?

The 1.4 (140 offensive rating) when they pass out of help defense in the post, including 1.5 on 3-point attempts.

Then there are actions like this, where the Celtics slip the big rangy wings they have.

But even on this play, the wide open floater that Jaylen Brown is taking turns out to be preferable to the open catch-and-shoot corner three-pointer.

Step one has to be convincing Boston they don’t get to dictate terms. They’ll be playing uncomfortable 2000’s basketball. And if that means your weakest defender gets torched, so be it.

THE MEMPHIS GAME

You can try what Memphis did, which was putting their center, Jaren Jackson Jr., on Jrue Holiday and helping off him specifically. They dared Holiday to make wide —and I mean wide— open corner threes.

It worked, Holiday missed a ton of threes. Boston will have counters for it next time.

But what Memphis did do for the most part was stay home on the other shooters. Boston took 47 threes, four fewer than their season average despite Memphis’ breakneck pace. Holiday took 17 of those.

Boston took 38 catch-and-shoot 3’s which is higher than their season average, but Holiday took 13 of them. Pritchard took six, higher than his season average, but again, the pace comes into play.

Still, Memphis allowed 47 threes and Tatum, White, and Tatum, White, and Porzingis shot 6-of-27 from three. ³

But more than one pro personnel staffer mentioned when I asked about Boston that their question was whether so much of Boston’s success is based on team’s inability to gameplan during the regular season as opposed to the playoffs. They don’t deny Boston can win in the playoffs; they just won the title. But if this year’s team isn’t quite the same as last year’s, that at least opens the door.

SO CAN ANYONE BEAT THEM?

In order for Boston to be overrated, you have to be able to credibly believe any team will be able to beat these instincts and traditional principles that force them into the wrong defensive decisions.

That’s where folks are understandably skeptical about anyone knocking off Boston.

Look at these coaches in the East:

• Tom Thibodeau

• Doc Rivers

• Kenny Atkinson

• Jamahl Mosley

Who’s coming up with not only the gameplan to invert the percentages, but getting his players to commit to it?

Let’s cross off Thibs and Doc right away. Neither of those guys are innovators. Great coaches, excellent at instilling programs, win a lot of games. But not innovators.

Atkinson? My biggest complaint with the Cavs through two games is that they specifically have allowed Boston to absolutely bomb from deep. They also play two bigs, which makes this challenge even tougher.

Mosley though… Mosley’s an interesting one. He gets to gamble with coverages because they would be an undermanned underdog. No one would take them seriously.

But you have to even get to that matchup and Boston may just not see them.

In the West?

• Mark Daigneault

• Jason Kidd

• Taylor Jenkins

• Michael Malone

• Mike Budenholzer

• Chris Finch

The only coaches who have a prayer of having the initiative to tailor their scheme and the personnel to do it are Daigs and Jenkins. Everyone else is either too rigid or doesn’t have the personnel.

THE LESSON AND A WARNING

Boston’s awesome, and this isn’t an attempt to take away what they do or how well they’re coached or how good the talent is. This isn’t gimmicky, it’s just exploitation.

But this season, they’re pushing the limits of what they do. I’ve seen this before. The Warriors in 2015 were the first team to win the title by leading the league in both pace and defensive rating. The year after they were a really good defense, but not elite, with an offense that felt they were invincible.

Feels similar. That team finished one quarter short of a title.

Boston was a balanced monster last season. This year, they’ve taken their math advantages to the furthest extent.

The Celtics aren’t unbeatable, but it takes something novel and different to beat them and most almost the entire league simply isn’t equipped to find that solution.

If no one does, we’re going to be the closest we ever have been with having to accept that basketball, as a sport, has simply been solved mathematically, and no one wants that.

1. Tatum is much more formidable; he’s an MVP candidate this year for a reason. He’s at 1.22 points per possession on ISO non-threes. That’s higher than the Celtics’ points per possession on catch-and-shoot threes. But with a defender within two feet of him? Tatum is still at 41% from 2-point range.

2. Over the course of an average game (100 possessions), you just got blown out by 25 if all you did was attack a relative weakness of Boston’s and they did the thing they do the most of.

3. Did I mention Boston was on a back to back?