How the Boston Celtics switched their means towards an NBA championship

On the floor, it was a seemingly mundane baseline out-of-bounds (BLOB) play on the 4 minute and ten second mark of the second quarter that the Dallas Mavericks had been priming to run. However as is true of high-stakes NBA basketball, there are a number of layers hidden beneath the supposed simplicity of an NBA possession.

Once you consider how the Boston Celtics defended the Mavs all through the course of the 2024 NBA Finals, the aforementioned possession makes a ton of sense. Towards essentially the most prolific nook taking pictures group within the league in the course of the NBA season, the Celtics held the Mavericks to a complete of twenty-two corner-three makes an attempt (non-garbage time) in 5 video games — a median of 4.4 makes an attempt per sport, effectively beneath the Mavs’ regular-season common of 11.3. Whereas “pushing the best buttons” would nonetheless be an apt technique to describe the Celtics’ protection when it got here to limiting a sometimes potent offense, “flipping the right switches” could be extra apropos — each within the figurative sense and within the literal method by way of which the Celtics threw a ton of switching the Mavs’ means.

The maneuver of switching assignments round a display will be deceivingly easy to the informal eye. It could look simple, however there are a number of components to contemplate: the timing of the change, the compatibility of the defenders concerned, the potential of counters (e.g., slipping the display to realize separation from the change earlier than it may be established), and a number of other different underlying components at play. Ball-screen possessions are the commonest switchable actions, however the problem is exponentially elevated when switching off the ball — notably, in a state of affairs akin to a baseline out-of-bounds set.

So when the Celtics had been confronted with a “pick-the-picker” (also called a “screen-the-screener”) motion in the course of the aforementioned BLOB state of affairs, a seemingly distant connection was made between a dialogue LeBron James and JJ Redick had in an episode of the Thoughts the Sport Podcast.

Earlier than we delve into that dialogue — and to set the stage for the connection — right here’s the play in query:

Protection is commonly a mental-checklist train, which is simple in concept however troublesome to tug off whereas mired within the fast-paced nature of an NBA possession. The very best defenses within the league are neither element inadequate nor velocity susceptible — that’s, they be certain to cross each “t” and dot each “i” with out the necessity for slowing issues down. Fairly clearly, their opponents received’t accommodate them within the latter regard.

If the possession above was to be made right into a guidelines, it will look one thing like this:

• Keep true to the precept of taking away the corners (Al Horford was capable of keep dwelling in opposition to Derrick Jones Jr. on the weak-side nook, whereas Jaylen Brown efficiently saved tabs on Kyrie Irving on the strong-side nook).
• Ensure that neither Irving nor Luka Dončić spends appreciable time dealing with the stay ball and ending the possession.

In these two regards, it was an astounding success. The Mavs had no selection however to feed the ball to PJ Washington, who tried to create his personal scoring alternative however shuffled his toes attributable to a well timed rotation by Sam Houser.

When shining a magnifying glass on the possession to infer why (and the way) each merchandise on the record was checked off, peep at each Brown and Jrue Vacation — and try to know their maneuvers whereas a James proposal about defending “pick-the-picker” BLOBs to Redick is overlaid:

Who would’ve thought that merely switching the inbounder’s defender would throw a wrench into the Mavs’ BLOB? However that’s precisely what Vacation and Brown do; as a substitute of chasing Irving towards the nook, Vacation switches off of him and switches onto Dončić, whose preliminary defender (Brown) drifts towards the nook to change onto Irving. Vacation’s maneuver, due to this fact, is to plug a spot created by an try and plug one other hole.

With each Dončić and Irving in no place to get the ball again to create one thing out of nothing, Washington is pressured into a job he’s not snug enjoying, leading to a bumbling try to attain on the rim.

If such a phrase exists that may seize the essence of what the Celtics’ protection was all about in these Finals, it’s most likely this: “Take away their greatest offensive choices and stay with the result produced by all the pieces else.” Their nook three philosophy was born out of this method: nobody was allowed a nook look, particularly Dončić and Irving; everybody else was allowed above-the-break seems, save for Dončić and Irving.

A lot has been praised — and maligned — in regards to the Celtics’ mathematical method to the sport. Folks aren’t eager on understanding the obvious problem of making use of numbers to a sport that has handled such figures as a supplementary and secondary side. However it’s not as onerous to know as many individuals assume: three is larger than two, which doesn’t require an engineering diploma to soak up.

However that’s an idea that applies to just one aspect of the ball. Whereas the Celtics have embraced the three > 2 philosophy by spreading the ground and totally embracing a 5-out offense, they’ve additionally utilized its reverse on protection — that’s, two is lower than three. In that regard, their philosophy can also be fairly easy: make opponents take robust twos in lieu of trying environment friendly threes.

Once more, that’s the place their anti-corner philosophy is available in. However it additionally applies to the character of the twos they’re keen to surrender, and which of them they’re not permitting.

Peep on the commonality between these shot profiles from the Mavs, per Cleansing The Glass:

• Sport 1: 33% rim frequency (fifty fifth percentile), 38% mid-range frequency (79th percentile), 29% three-point frequency (tenth percentile)
• Sport 2: 30% rim frequency (forty second percentile), 39% mid-range frequency (83rd percentile), 30% three-point frequency (14th percentile)
• Sport 3: 32% rim frequency (forty eighth percentile), 40% mid-range frequency (86th percentile), 28% three-point frequency (ninth percentile)
• Sport 4: 37% rim frequency (eightieth percentile), 31% mid-range frequency (forty third percentile), 32% three-point frequency (twenty first percentile)
• Sport 5: 30% rim frequency (thirty eighth percentile), 24% mid-range frequency (twenty first percentile), 45% three-point frequency (ninetieth percentile)

On the mixture, the Celtics had been capable of put a lid on the rim whereas additionally taking away the three-point line — whereas additionally funneling the Mavs’ shot makes an attempt towards the mid-range space. The nook three vs. above-the-break three battle was additionally a subplot of this overarching theme, however one other notable stat that captured the Celtics’ method: the Mavs solely had a complete of six alley-oop makes an attempt in 5 Finals video games, a median of 1.2 makes an attempt per sport. That may be a far cry from the three makes an attempt per sport they averaged of their 17 playoff video games previous to the Finals.

It was on the grandest stage, with the lights switched on at their brightest, that the Mavs hit the proverbial wall, courtesy of the Celtics walling off the rim and switching virtually at will. If the Mavs wished to attain, they’d need to bleed for it — and no possession captures that state of affairs with extra accuracy than on a possession involving a Mavs staple half-court set.

We should as soon as once more look again to see what labored prior to now:

So as to admire what the Celtics did to remove what victimized lesser groups:

Loads of odes and tributes can be paid to the Celtics’ offense — how each member of their five-man lineup was each little bit of a shot creator as a shot finisher, the way it made defenses overexert and overstretch themselves to their utmost limits, and the way it was essentially the most environment friendly in NBA common season historical past.

However as a rule, a top-10 protection is the deciding issue behind what constitutes a championship group. The Celtics — third in total defensive score in the course of the common season, first in half-court defensive score — grew to become the newest in an extended line of elite championship defenses.

There was no “on” change to be flipped, no gear to shift into. The change was all the time there — within the type of, fairly actually, switching their opponents into half-court oblivion.