Special thanks to Coach Anthony Macri of HoopsWorld and Pro Training Center for his help on this post!
Everyone knows the Boston Celtics and Miami Heat have two of the best defenses in the NBA, giving up respective opponent FG%s of 43.5% and 43.1%. But these squads, who look destined to meet in a potentially epic second round series, achieve their impressive figures through fundamentally different defensive philosophies.
This is, in part, a reflection of two smart defensive schemes that take advantage of their personnel in order to best profit from strengths and mask weaknesses. The Heat’s defensive specialty is the ability of their athletic wings, LeBron James and Dwyane Wade, to cause havoc and make up for the mistakes of teammates. The Celtics’s D, on the other hand, is designed to take advantage of Kevin Garnett’s incredible ability to organize and communicate with his teammates.
There are certainly overlaps in execution. Both teams give great effort, communicate well, are focused and energetic, and rely on prescient rotations to lock down opponents. However the are also essential differences between the Heat’s and Celtics’ defenses leads the Heat do whatever they can to pressure the ball, while the Celtics try to pressure the passing lanes through technically precise positioning. The Heat look to disrupt by getting eyeball-to-eyeball pressure and force defenses to read and react in the face of active, swarming limbs. Meanwhile, the Celtics want to prevent ball reversals by angling everything to the baseline and getting hands in passing lanes to stagnate the opposition’s offense.
Here are some of the ways these two philosophies manifest on the court:
Despite an aging roster, the Celtics have created 150 more turnovers and have stolen the ball 111 more times the Heat.** This is in part because in the NBA, pressuring the ball doesn’t create turnovers if you don’t also jump passing lanes. The Heat aren’t all that aggressive in the passing lanes, in part because aside from Joel Anthony, Miami’s big men aren’t swift enough to make up for bad gambles. Boston, conversely, plays aggressively in the passing lanes while pressuring the ball a bit less than the Heat.
Watch how, in this video, DeMarcus Cousins is not being bothered at all by his defender, but he can’t find an angle to kick the ball out. Although the defense appears almost passive aggressive, it causes Cousins to eventually turn it over to Paul Pierce, who forced his man back door. The second and third clips show off the opportunistic defense of Kevin Garnett and Rajon Rondo. In addition to philosophy, these two excel at getting their hands on the ball.
The Heat, despite not having a traditional shot blocker in on the court other than when Joel Anthony sees major minutes, swat the seventh most blocks in the league. This is in no small part because Dwyane Wade and LeBron James contest shots at the rim better than any wing tandem in the NBA. Meanwhile, the Celtics block comparatively few shots—ranking 29th in the NBA– in part because their overall defensive scheme places help defenders in position to take charges rather than erase shots from the weakside. The Heat, and especially James Jones, do rotate hard to cut off drives, but they also rely on James and Wade’s ability to come out of nowhere to influence shots. In this clip, LeBron and Wade put on an absolute show, blocking three straight Memphis Grizzly fast break attempts.
Pick and Rolls
The Celtics defend the pick and roll exceptionally well, especially the side pick and roll. The on ball defender, in this clip Pierce, jams the screen, sending the ball handler Danny Granger to the baseline, where a big help defender waits ready to corral the ballhandler. In this clip, Granger runs into what is essentially a soft trap along the baseline, intended to prevent middle penetration and make it more difficult to split the screen. When Granger kicks to Roy Hibbert, Garnett rotates hard and forces Hibbert into an awkward runner.
The Celtics have been playing together so long, they can effectively operate a few different schemes, depending on the opponent. In the second part of this video, they let Stephen Curry go middle and get in position to bother his pull up, while still rotating aggressively to David Lee and preventing him from scoring on the roll.
The Heat sometimes corral, as they did masterfully to slow down the San Antionio pick and roll attack, but with Joel Anthony on the court, they’ll also blitz the ballhandler in side the pick and roll. This active trap, which is often a “hard show and recover,” is meant to prevent direct passes to open players with this pressure, forcing the ball away from the popping or rolling screener. If the ball goes to the screener, the trap should give a third, rotating defender time to get over. Here, Wade deflects the first pass and almost comes up with a steal, notice Jamal Magloire rotating to the popping screener. In the second clip, they corral Mike Conley, then furiously collapse when he finds Marc Gasol on the roll. But Miami’s big men can’t really bother Gasol’s hook shot. That’s when 6-4 Dwyane Wade sprints in from the weakside to get the block.
According to Syngery, as a result of their respective strategies the Heat give up fewer points to the ballhandler, but the Celtics defend the roll man better.
The Heat don’t force their opponents into a high turnover rate, but they have the 9th best rebound rate in the league, while the Celtics are only the 20th best. This is because the Heat do a better job swarming to the ball and rebounding as team. It may also be because their pressure defense puts players in better box-out position than the passing lane playing Celtics. The Heat don’t force as many dead possessions as the Celtics, so it’s vital that they hit the glass hard. Despite a supposed size disparity, they’ve twice out rebounded the Los Angeles Lakers by a combined 10 boards.
Assist rate against
This is a great statistic to see if a team’s defense is preventing its opponents from running their offense. For instance, the Golden State Warriors give up the highest percentage of assisted field goals, a staggering 64.18%, while the league’s best defense in Chicago is surrenders a 55.52% rate. Given the way the Celtics keep the ball on one side of the court and impose isolation on the ballhandler, it’s no surprise they have a lower assist rate against (56%) than the Heat (58%). If you can handle the pressure, it’s slightly easier to run offense against the Heat defense.
In this clip, Boston denies a ball reversal by Paul Millsap then forces Earl Watson along the baseline, preventing any kick outs. Notice how the Celtics are in constant movement in order to maintain their ball-you-man passing lane principles. Watson’s journey is technically a ball reversal, but when it comes from a contained dribbled like in this instance, it’s the least effective form of ball movement and the defense is not stretched out of position. The result is when Watson goes to make a pass, the Celtics are in perfect position to get a deflection and go the other way. Watch how Boston rotates to the threat, not the man. They are content to let Watson handle 18 feet away and prevent him from finding a more skilled teammate.
Now look at how the Heat scramble and swarm. In fact, they probably over rotate by sending three defenders to the rolling screener. But they do force the Kings to find their third or fourth option, and James Jones races to get a hand in the face of the shooter. The contested shot misses, and four Heat players go to the glass to recover the possession.
This is the area that I believe truly separates the two teams. The Celtics instinctively trust and their system and teammates, while the Heat are still building that connection. In part, this is due to the fact that the Heat don’t often play with five trustworthy defenders. Players like Eric Dampier and Mike Bibby are too calcified to cover for teammates’ mistakes, whereas the Celtics, with Garnett directing traffic, are almost always in perfect position to help each other. Boston, by virtue of its experience together, is also more adept at adding wrinkles on a game to game basis to take away specific elements of a team’s offense.
However both teams have recently struggled a bit with this root fundamental of their defenses. If the two teams meet in the playoffs, the winner will likely be the squad that exhibits the most trust on the defensive end.
The Heat, with their defensive strength on the perimeter, must smother the ball to fatigue opponents and swarm at the rim to wipe away miscues. Conversely the Celtics are so solid inside, they can take their chances in the passing lanes on the perimeter.
As systems go, I prefer the Celtics’ approach (and roster). I think it better defrays the responsibility across the team, while Miami’s relies on two to four versatile defenders to disrupt opponents. However, it is a glowing testimony to the designers of each teams’ defense that their systems so elegantly exploit the divergent talents of the respective rosters.
**Both teams play at an almost identical pace–Mia at 91.0, Boston at 90.4–so I did not adjust for pace throughout in this post.