The Warriors’ season-long defensive philosophy is paying dividends on the grandest stage

If there’s one catch-all phrase that defines the philosophy of the Golden State Warriors defense throughout this season, it’s this: “Prevention is better than the cure.”

If they can help it, the Warriors would rather not let their opponents be in a position to score in an efficient manner. If they can stop someone before they can get downhill — with two feet touching the paint — they will do so.

That starts at the point of attack. There’s no use in keeping opponents off the paint if they are able to get past the first line of defense. Once that domino falls, there’s a greater chance the rest will topple over — a defense in rotation, plugging holes slower than the rate at which they’re being created, etc. — and the plot is entirely lost.

Stopping opponents from touching the paint has been a major point of emphasis for the Warriors. It was a huge component of their early regular-season defense, once considered dominant and historically transcendent. That fell off to a more “tame” level, but still relatively elite compared to the rest of the league.

It’s easy to forget that while the Warriors are facing an opponent that excels in limiting paint touches and attempts at the rim, they themselves have been elite in that department — slightly more so than the Boston Celtics.

Consider this: The Celtics were 2nd in opponent rim frequency during the regular season, at 27.7%. The only team that bested them in that department? The Warriors, who only allowed 27.0% of their opponents’ shots to be taken at the rim.

One reason why it’s easy to overlook that little statistical nugget is due to the differences in personnel. The Celtics’ success at walling off the paint and the rim stem from a combination of excellent point-of-attack defense, excellent screen navigation, and having the ultimate clean-up man in the backline in Robert Williams III.

The Warriors have the excellent point-of-attack defense. They have the screen navigation chops to compete. But they’re missing the bona-fide rim protection component that the Celtics have in Williams III. The Celtics averaged 5.8 blocks per game during the regular season, 2nd in the league. The Warriors, on the other hand, averaged 4.5 blocks — a middling 18th.

That’s where their philosophy of prevention above all else comes into play. If you can stop your man before he can get anything going, that’s the ideal outcome. It eliminates the need for the rest of your teammates — especially in the backline — to compensate, rotate, and help.

A prime example of such a philosophy happened during the Celtics’ first offensive possession in Game 5. The Celtics have been unashamedly hunting the weakest link within the Warriors’ lineups, whether it be Stephen Curry or Jordan Poole.

Sensing this development, Curry organized the defense in a prescient manner:

Look closely at Curry as Jaylen Brown brings the ball past the half-court line. Instead of starting on Marcus Smart — as he usually does — he directs Otto Porter Jr. to take Smart instead, while he defends Williams III.

Intentionally taking a center with a 7-inch height advantage seems to be a weird decision to make. But Curry has a good reason for it: “pre-switching” Porter Jr. onto Smart is a precautionary measure for a Smart-Jayson Tatum pick-and-roll, a tool the Celtics have spammed all series long to hunt Curry on a mismatch against Tatum.

Instead of a mismatch, it’s a wing-to-wing switch — Tatum goes from being guarded by Andrew Wiggins to being guarded by Porter Jr., who is successful at stifling Tatum’s drive. With help from Wiggins, who stunts at Tatum during his drive, they force a turnover.

Pre-switching has been a valuable tool for the Warriors. It serves a double purpose: to involve more capable point-of-attack personnel in lieu of defenders who can be easily compromised; and to throw a wrench into the defense’s intentions and render half-court possessions stagnant and flowless.

Pristine communication is key to successful pre-switching. Peep at Curry and Draymond Green communicating with each other to pre-switch once Curry’s man — Derrick White — comes over to set a screen for Brown:

The Celtics are forced to improvise with a Smart “Keep” action — a fake handoff. But Curry isn’t fooled by Smart’s fake, and he stays in front of Smart to stifle his shot attempt. Instead of a Brown switch onto Curry, the Warriors’ pre-switching forces the Celtics to settle for an inefficient shot by a lesser offensive threat.

Mixing up coverages, throwing out different looks, and timely help have been the keys that have unlocked the Warriors’ suffocating defense — and in turn, have rendered a Celtics half-court offense largely inept (94.3 half-court ORTG in the NBA Finals, equivalent to 20th during the regular season). In their attempts to hunt for the lowest hanging fruit, the Celtics have narrowed their offensive approach, which has made them all the more vulnerable to sudden changes in defensive schemes.

The Celtics attempt to hunt Curry in the possession below through a combination of two different screening actions: “Wide” action, followed by a double ball-screen alignment. When their attempts are stifled, they try one last time to get Curry involved against Brown.

Which is when the Warriors decide to spring a trap — literally:

Curry and Klay Thompson blitz Brown around the ball screen. White slips and makes himself available on the short roll, and attempts to attack the rim straight on — instead of punishing a tilted defense by kicking out to the weak-side wing or corner.

This decision proves fatal, as Green is in perfect help position as the low man to vertically contest White and stonewall him completely.

Lost amid the Wiggins performance was Green’s bounce-back game, particularly on the defensive end. His off-ball roaming and rotations as a help defender were vintage Green. The Celtics were held to 36 points in the paint; a mere 13% of their shot attempts came at the rim — a development that had Green’s fingerprints all over it.

His combination of fundamentals, length, and intelligence were on full display — most notably against Brown. Green has read the scouting report on Brown, who has a notorious reputation for being a less effective driver when forced to use his weaker left hand.

Green knows that to force Brown to his left is one-half of the battle won, which is preventing him from getting to the rim altogether. The other half is to force him to make a bad decision:

Green shades Brown to his left, with Curry showing early help from the weak-side corner. True to the scouting report, Brown has difficulty getting past Green while dribbling with his left. With Gary Payton II “splitting the difference” between the corner and the wing, Brown kicks out in desperation — into the waiting hands of Payton II.

Brown’s weakness is so pronounced that the Warriors are content to give up middle penetration — something that’s normally considered antithetical to their philosophy, let alone general defensive principles — to funnel Brown into a brick wall.

As the undisputed defensive leader of the Warriors, Green sets the tone. A locked in defensive maestro trickles down to everyone else on the roster; a connected and intelligent defensive unit flattens out possessions, keeps everything mostly in front, and erects a figurative fortress around precious real estate.

That’s when you get a possession like this:

And this:

In 5 games, the Warriors have allowed only 18.9% of the Celtics’ shot attempts to be taken at the rim — much lower than their league-leading rate during the regular season.

Sticking to their season-long defensive philosophy of rim prevention — buoyed by personnel, versatility, connectedness, and basketball IQ — has paid massive dividends. If the Warriors manage to clinch a title in the upcoming days, it will no doubt deserve a significant chunk of the credit.