How Celtics shut off the Mavericks’ offense in Game 1 of 2024 NBA Finals

In the NBA, there are certain buzzwords that are instantly associated with certain players, teams, and coaches. When you hear the term “triangle offense,” you think of Phil Jackson and his championship-winning Chicago Bulls. Los Angeles Lakers“Seven Seconds or Less” by Mike D’Antoni Phoenix Suns In the mid-2000s, he pioneered the now-ubiquitous pace-and-space era. A lesser known, but perhaps just as influential, concept was the “corner offense” promoted by Rick Adelman and the Sacramento Kings of the early 2000s.

At the heart of both the triangle and corner offenses is the split action. This is Golden State Warriors‘ The dynasty credits both Jackson and Adelman as the originators of their vaunted motion offense, a split action still associated with the Warriors but which has become more common in the NBA.

One reason most observers today probably wouldn’t recognize the common split action is because it’s simply different in location: When you hear the split cut, you’re probably referring to the low-post cut made popular by the Warriors, who, with the help of Stephen Curry’s otherworldly talent, sliced ​​up opponents.

The split action settings that most people will imagine are probably something like this:

While Jackson’s triangle principle also called for the post playmaker to occupy the low block (similar to Steve Kerr’s interpretation of the split action above), Adelman’s corner offense had the big man hub higher at the elbow, i.e. in the high post. In that respect, the Kings of the early 2000s employed the so-called “high post” split, which is the opposite of Kerr’s version in position but similar in concept and philosophy.

What is the overall philosophy of split action? Results vary depending on the defense’s response, but the initial goal is almost always to create space for shooters around the split-cut screen. If the defense chooses to switch their action, it creates two mismatches: a faster perimeter operator with a bigger, slower player, or a stronger player guarded by a smaller defender. Split-cuts also create slip opportunities as a counter to a switch or in response to a “top lock” (getting in between the off-ball player and the screen to prevent them from using the screen).

Although not particularly known for its extensive use of split action, Boston Celtics Use it to your advantage and hopefully provoke a defensive response that will lead to one of the aforementioned outcomes. Similar to Adelman’s version (and the Denver Nuggets’ version), the Celtics like to play split cuts through the high post.

Unlike Adelman’s version, where the split cut occurs on the ball side, the Celtics’ split cut occurs on the opposite side.

There’s a deeper meaning behind Jayson Tatum’s attempt to set a screen for Derrick White. Bypassing the traditional method of finding a mismatch and having Tatum move the ball off the field and set a screen for Kyrie Irving’s guard is a somewhat unconventional approach to drawing favorable matchups, but like split action, it’s gained a fair amount of traction in NBA circles and is quickly becoming a conventional tactic. More and more teams are having their perimeter creators set off-ball screens in this manner.

In the above case, Derrick Jones Jr. and Irving managed to stay home, and White quickly moved to the dunking spot, forcing Irving to chase him down. At about the same time, Jrue Holiday faked a handoff and kept the ball on a sudden drive. This put Irving in a dangerous situation where he had to help White on Holiday’s drive. Holiday saw the crease and tossed the ball to White for an easy layup.

of Dallas Mavericks“The version is nearly identical to the Celtics'” — but the main difference is in how the Celtics defended the action.

Knowing that Holiday and Tatum would likely just trade split cuts, Irving tries to get a head start on Holiday by rejecting the screen and coming off of Jones’ handoff. What Irving doesn’t expect is Holiday to recover quickly, get through the screen, and alert Irving to his presence behind him, preventing him from getting ahead. Holiday’s partner in the pick-and-roll defense is Al Horford, adding an extra sense of security and safety. Horford justifies both by smothering Irving’s drives and forcing him into mistakes.

More notable are White as the weak-side corner (the “low” man) and Jaylen Brown as the ball-side or strong-side corner.

Horford effectively stifled Irving’s drives, keeping Brown from needing to help from the strong side corner and White from venturing into the paint to create skip opportunities for P.J. Washington. The confidence that Horford would handle the action up front eliminated the need for rotations, which has been at the heart of how the Celtics have approached defense in this series.

While it may be overly simplistic to pin small battles on the fate of the entire game, this series may come down to who wins the battle of the corners. The intriguing story this series presents is a showdown between the Mavericks, who make the most corner 3s (11.3 corner 3s per game and 12% corner 3s in the regular season, both first in the league) and the defense that is best at limiting corner 3s (7.7 corner 3s per game, third-best in the regular season; opponents made 8.1% corner 3s, fourth-best in the regular season).

In that regard, it’s important for the Celtics to give Doncic and Irving opportunities to help the team win. Personal A win is possible, but certainly not without resistance. If Doncic can reach the 30-point threshold (he did), the Celtics will have no problem as long as he puts up a fight for the team (26 shots). If Irving can back him up with 20-25 point performances (he didn’t), it wouldn’t be the end of the world.

Some notable stats: Doncic (30) and Irving (12) combined for 42 of the Mavericks’ 89 points, while the rest of the playoff rotation added 47. The team was held to just nine assists on 35 field goals attempted. Doncic had just one and Irving had two.

The Celtics’ stubborn refusal to get help from the corners is the root of the Mavericks’ predicament, but it also reveals a seemingly contradictory approach: They’re willing to let Doncic and Irving dominate the ball and try to score instead of finding their teammates in the most efficient scoring situations. At the same time, they’re also willing to let players other than Doncic and Irving score unless it’s from an efficiency standpoint.

The Celtics responded to the former primarily through two coverages.

1. With Al Horford on the floor, they were eager to switch things up to flatten the Mavericks’ half-court game, allowing defenders, including the cornerbacks, to do their jobs. The trust that Horford and other “lesser” defenders could isolate themselves against Doncic and Irving was largely justified.
2. With Kristaps Porzingis on the court, the Celtics elected to put him in drop coverage in pick-and-roll situations, which made the half-court possession a 2-on-2 effort, eliminating the need for the other three defenders to rotate and allowing them to trust Holiday or White to avoid the ball screen, which would have otherwise resulted in the Celtics switching out a screen action that did not involve Porzingis (i.e., switching 1-4).

The Celtics took the latter approach by simply having Porzingis guard the least threatening offensive player at the time and feeding the ball to him off the break, as in the example below, which left Josh Green free to launch an attack on his own.

If he forces a rotation from the corners, it’s only as a last resort, but switching everything up front limits his options, and then utilizing a “peel” switch to the corner to fill the hole created by the strong-side help, as Brown will do below if Irving chooses to kick the ball away.

But after beating Brown backdoor, Irving tried to score against a rotating Horford, who again forced a difficult shot and missed.

The Celtics’ approach paid off in a big way, holding the Mavericks to a playoff-worst 96.7 points per 100 possessions (77.1 points per 100 possessions in the half-court) in Game 1. While taking risks seems rather contradictory from a coverage conservatism standpoint, putting all of their resources on the two heads of the dragon and making the calculated gamble that the rest of the players would be mere supporting players rather than poking where it hurt was a wise decision.