In Boston's eight wins in their last 10 games, the Celtics have been sharp on defense, sporting a 94.7 defensive rating. They've scored over 110 points in seven of those W's (103 vs. Indiana), but it's really been their D that has been the source of their success and furthermore, given this team their identity.
The modern NBA is played on the perimeter and with superior defenders like Avery Bradley, Marcus Smart, and Jae Crowder, the Celtics smother opposing teams outside the paint. Especially when they go small, they can switch every pick and take away an opposing team's first and second option.
Even in an unfavorable switch, they'll stay home. Remember that loss to the Mavericks where Isaiah Thomas and Avery Bradley were often caught in switches guarding the much taller Dirk Nowitzki? They almost never ran an additional defender at the ball. Brad Stevens would rather give up the soft contest from a shorter player than send an another man and have the defense rotate.
But against the Magic on Friday, there seemed to be a change in philosophy, at least for the night. When the Celtics got crushed in Orlando back in late November, Nikola Vucevic put up a solid 18 & 10 in the Magic's 110-91 win. They stuck to their guns in that game, rarely sending help to Vucevic on the low or high block. He consistently ate up the smaller David Lee and Jared Sullinger.
Vucevic is one of the most proficient scorers on the low post. For the season, he ranks in the 71.8th percentile on post-ups, scoring 0.93 points per possession; that's on par with DeMarcus Cousins and ahead of Marc Gasol, Brook Lopez, and Jahlil Okafor. To make matters worse, because of their relative lack of size, the Celtics get posted up more than most teams. They're second in the league with 507 post-ups against. By comparison, the Toronto Raptors are last with 269.
To Boston's credit, they're above average defending it, ranking in the 58.6th percentile and averaging 0.84 PPP. Teams are more than willing to go into the post against the Celtics--who wouldn't with Crowder, Smart, and Bradley patrolling the perimeter--but they've been rudely greeted by some not-to-shabby defense in the paint. The trio of Jared Sullinger, Amir Johnson, and Kelly Olynyk form a pretty decent wall on the block, finishing in the 79.8th, 64.4th, and 57.7th percentiles respectively against the post up. For what it's worth, that puts Sullinger in the same class as Greg Monroe, Johnson with Al Horford, and Olynyk with Zaza Pachulia. With the trade deadline inching closer and closer, some fans will still clamor for a rim protector, but so far, the team is doing just fine.
But even with the numbers seemingly in Boston's favor, they turned the tables against the Magic. Jared Sullinger guarded him on most possessions, but as soon as he touched the ball, there was a guard dropping down to double in order to force Vucevic to get rid of it. Maybe it was because Orlando is an average three-point shooting team. Maybe it was forcing shots from the perimeter would generate more transition looks. Regardless, Vucevic could not find a rhythm down low.
When help didn't come, Vucevic had his way:
But when they doubled down on the big man, it either lead to a turnover or a missed shot:
It's unlike the Celtics to do so much doubling, but since going small, they've excelled at creating havoc on the defensive end and generating turnovers and transition points in the process. However, it's important to note that they doubled Vucevic with their more traditional starting lineup of Sullinger at the 4 and Johnson at center. Some might see it as a sign of weakness as if the team doesn't trust it's post defense, but I think it's more a sign of aggression. It takes offenses out of their first look and puts them in scramble mode. Boston has thrived in helter skelter ball and scored 21.4 points off turnovers in their last ten games. That's tops in the NBA. This could be Orlando-specific, but we'll know more later this evening when the Celtics wrap up this home-and-home series in Orlando.