This has been a weird season for the Portland Trail Blazers.
At first they were a surprise: fast out of the gate, on top of the Western Conference and well ahead of preseason expectations. For a while, they didn't cool off and Portland seemed like legitimate contenders.
And then, finally, they normalized. The preseason fringe playoff team began to lose, sliding to the middle of the Western Conference playoff pack. A defense that had been statistically below average all season began to catch up to them, and the rising stardom of Damian Lillard could no longer sustain.
And now we're left with what Portland has probably been all season: a delightfully overachieving roster with no hope of postseason success.
But what's particularly quirky about this team isn't their surprising rise in the West: it's how their analytics-based approach to basketball is actually hurting them on the defensive end.
On offense, they generally hunt corner threes and rim pressure—the two areas of the floor that generate the most points per possession on average. Although LaMarcus Aldridge shoots a ton of mid-range jumpers, his 42.2 field-goal percentage, per NBA.com, from that area of the floor makes it tolerable.
Not to mention that his ability to draw the defense towards him in pick-and-pop situations actually creates three-point shot opportunities for teammates. In a backwards sort of way, Aldridge's penchant for taking analytically poor shots actually fuels the taking of analytically approved shots.
On defense, Portland applies the reverse approach: Take away three-pointers and rim pressure and force opponents into mid-range shots.
The problem, however, is that Portland's adherence to this strategy is actually hurting them. Thus far this season, they've allowed 1,103 shots from the 15-19 foot range—good for the ninth most in the league.
The two teams on top of this list are the Indiana Pacers and San Antonio Spurs, two of the best defensive teams in the league. This would seem to at least indicate some sort of correlation between forcing mid-range shots and playing good defense, and that Portland is therefore a solid defensive team.
It's just that there's a crucial difference between the elite defenses and Portland. Whereas San Antonio and Indiana are allowing a field-goal percentage of 39.8 and 40.7, respectively, from that 15-19 foot range, Portland is allowing a 42.7 field-goal percentage—tied for second worst in the league.
Though the percentage difference seems small, over the sample size of 1,000-plus shots, that difference becomes significant. And in terms of overall defensive rating, we can see that at least partially reflected. Indiana is first, San Antonio is fourth and Portland is 18th.
On the court, San Antonio, Indiana and Portland employ similar strategies. In pick-and-roll situations (the lifeblood of most offenses), they have the defensive big drop back towards the basket, protect against drives and pass to the roller.
The defensive guard, meanwhile, has two choices: fight over the top and trail the ball-handler from behind, or go underneath the screen. Against better shooters, they will fight over. Against poor shooters, they will go underneath.
During the time it takes the defensive guard to get around the screen, it's the job of the big to handle two offensive players at once. But by giving enough space, the defense is hoping the the ball-handler will pull up for a jumper in that mid-range area.
Here is San Antonio playing this type of pick-and-roll defense against Phoenix's Eric Bledsoe. The strategy in this case is to go underneath:
Tim Duncan drops, Parker goes underneath both the screen and re-screen, and Bledsoe pulls up when he senses the space. Parker is able to somewhat get a hand up, and Bledsoe misses.
That's picture-perfect execution of pick-and-roll defense, and the key is Parker. His ability to fight through the screen and provide at least a partial contest is enough to make the shot tough.
The problem in Portland is how their guards are handling the pick-and-roll, and not the overall strategy. Though forcing mid-range shots (like San Antonio does above) is ideal, you can't simply give up uncontested shots to guards regardless of location.
In the playoffs, Portland will be facing ball-handlers who can all hit those types of shots with regularity: James Harden (likely in the first round), Tony Parker, Stephen Curry and Russell Westbrook, just to name a few.
Too often, Portland's guards—and in particular Damian Lillard—are getting hit or caught up in screens. Because the big is dropping so far back, he is unable to contest any pull-ups. It's on Lillard and the other perimeter players to somewhat disrupt the shot attempt.
With Lillard taking on an even larger offensive role this season, it has been tough for him to handle the strain on both the offensive and defensive ends of the floor. While offense can often be guided by adrenaline—there's nothing like having the ball in your hands to perk you up a bit—keeping up the energy on the defensive end is very difficult.
That's what's so demanding about playing point guard in today's NBA: Not only do you have to make great decisions in the pick-and-roll on offense, but you have to deal with big and physical opponents hitting you for 40 minutes each night on the other end of the floor.
Of course it might not be a function of Lillard's physical fitness: It could be a matter of effort. From our outside perspective, it's difficult to tell. But either way, he's done an average-to-below-average job of fighting through screens all season. According to Synergy Sports (subscription required), he ranks in the 29th percentile in the league guarding pick-and-roll ball-handlers. As a whole, the team ranks 28th in the NBA.
Take a look at this play against the Golden State Warriors, with Lillard guarding Curry. As Curry dribbles into the wing, Andrew Bogut rolls in to set the side pick-and-roll. Per Portland's strategy, Nicolas Batum drops into the paint.
Yet there's plenty of time before the screen comes for Lillard to recognize that it's coming. It's also likely that a teammate called out the screen, giving Lillard time to prepare.
Still, Bogut crunches Lillard. To make matters worse, Lillard goes underneath. That's a cardinal sin against Curry, arguably the best shooter in the league. Because Lillard gets caught up in Bogut's body, he can't quite get there to contest. In effect, Curry now has a wide-open three-pointer.
These are the little details that take a defense from average to good. The stringent adherence to analytics on the defensive end naturally makes Portland a better defensive team. But it's on the players on the floor to make a good, and even great, defense, and Portland's current guards simply do not do a good enough job.
In the playoffs, opponent scouting reports become more in depth and look to find every advantage. Portland's first-round playoff opponent will almost certainly notice this tendency, and will do everything in its power to take advantage.
Throughout the season, Portland's guards have shown no indication of improvement. If the current course continues, expect them to watch any subsequent rounds of the playoffs at home.
Unless otherwise noted, all stats retrieved from NBA.com (Subscription required)