Quite a lot is happening in the Western Conference playoff race. Postseason fixtures like San Antonio and Oklahoma City are struggling. Minnesota is without Jimmy Butler for the foreseeable future. The Pelicans are surging, but thin. This has set up a power vacuum behind the top two teams, Houston and Golden State, ripe for just about any team in the contending peloton to push into a high playoff seed and home-court advantage. Maybe even an upstart like the Portland Trail Blazers.With 19 games to play, the Blazers sit third in the West, looking as likely as anyone to hold onto home court over the final month and change. Portland is on an 8-1 run, including six straight wins. Damian Lillard has averaged 33 points, 6 assists and 4 rebounds over that stretch. He has jump-started an uncharacteristically dormant offense, and the wins have followed. But it isn’t Lillard’s outbursts that have lifted Portland’s profile above where it’s been in past seasons. That would be the defense.After years of playing some of the worst team defense in the league, the Blazers are seventh in defensive rating on the season, according to NBA.com. It hasn’t been entirely smooth — after a strong start to the season, the team ranked just 22nd in January and 12th in February — but Portland seems to have righted the ship during this latest stretch. According to Basketball-Reference.com, the team had a 102.9 defensive rating during that stretch, which would put Portland at the top of the league if that were its season-long figure.The curious thing is the Blazers have done this without many of the obvious tells of a good defense. They don’t force many turnovers (third-fewest per 100 possessions); they give up free throws at an average rate; they are average to below-average defending the pick-and-roll and drives, according to data from Second Spectrum; and they don’t block an extreme number of shots or keep opponents out of the paint. In a way, it’s the opposite of the Milwaukee Bucks conundrum: The team gets results without the typical stats that go along with them.What Portland does do is stay in good position and limit high-value shots. According to Second Spectrum’s quantified shot quality stat, which takes into account shooter and defender position, as well as other variables, the Blazers give up the lowest quality shots of any defense in the league, at an implied 49.5 effective field goal percentage. This is in part because the team denies 3-point attempts, ranking fourth in opponent 3-point attempts per game, and keeps high-value corner-three attempts down.In fact, if we think about the Portland defense as a longer term proposition, there’s some reason to believe that the team’s defensive slide in January had as much to do with random chance as anything else. Over that month, the Blazers improved their defense as far as opponent shot quality goes, posting an implied 49.3 eFG% in that month, better than its current league-leading 49.5 figure. More goes into a defense than the X and Y coordinates of opposing shooters, but given Portland’s contain-first system, it’s crucial that the fundamentals held up even when the defense was struggling.The way that system works also allows for Lillard and backcourt partner CJ McCollum, not exactly lockdown defenders, to contribute to the defense without having to stick with their opponent. It involves dropping the defending big man very deep into the lane in pick-and-roll coverage and daring the ballhandler to shoot a pull-up. From there, the defense is set up to defend a drive or a pass to a roller, thanks to the deep-lying big man, and if the ballhandler pulls up or hesitates for even a half-step, Portland’s guards can fight over the screen and get back into the play to challenge.This isn’t always a sure bet — Lillard can still be bullied by bigger guards like Russell Westbrook when isolated — but overall it engages weaker defenders into the plan rather than leaving them to their fates and hoping they don’t spring a play-ending leak. In all variations on the design, the goal is to take the responsibility of containing dribble penetration away from the backcourt and to put it on center Jusuf Nurkic in the middle or more capable defenders on the wings. (Nurkic defends the most shots on a per possession basis and does so while holding opponents to an acceptable eFG and, crucially, not fouling at an astronomically high rate as he did early in his career — an important task for any defender playing the garbage-man role. This volume is a big reason the guards can play as they do. It’s also likely a big reason that Nurkic gets clocked in the face so often.) It doesn’t always work. But the team didn’t need a league-stopping defense; it needed to dredge its defense out of the depths of the league table.Ironically, it’s been the Blazer offense that has been holding the team back for much of the season, which is why Lillard’s recent dominance has translated so neatly into wins.Lillard isn’t as efficient as other star guards, such as Steph Curry or James Harden, but he’s having a career-best year running the pick-and-roll, creating 101 points per 100 chances, according to Second Spectrum, and 103 points per 100 chances on drives. These are very good numbers, particularly for a player burdened with as much defensive attention as Lillard typically gets, but not quite good enough to carry an entire team. McCollum has had a slightly down year, but he’s still hugely productive.Aside from Lillard and McCollum, no other Blazer can produce on the drive, which makes creating space difficult for this offense. Bad things happen when Shabazz Napier and Evan Turner drive. And insofar as the Blazers even have a post game, it’s not one that anyone would want to claim. They rank 27th in points per direct post-up, according to Second Spectrum, down among bottom-dwellers like Atlanta and Memphis. Nurkic takes the biggest share of blame here, registering fewer than 80 points per 100 chances created out of post-ups. There are some brights spots, such as the Lillard-to-Al-Farouq Aminu connection, but when every functional piece of the offense shares a vector through one or two players, the team will rise and fall as its stars do. Luckily, the Portland stars can thrive on their own, at least to a point. Lillard is one of the premier practitioners of the pull-up 3-pointer, a staple of the best offenses in the league — he’s shooting more than five per game and converting 38 percent of them. McCollum, meanwhile, takes his pull-up game inside the line. He shoots 40 percent on his pull-up threes but takes only three per game, compared with more than six pull-up twos. His season is a bit of a dropoff from his last, but an enviable one for nearly anyone else’s standards.The Blazers have one of the harder schedules remaining in the Western Conference playoff race and will have to rely not only on Lillard and McCollum to continue to lift an otherwise leaden offense, but also young players like rookie Zach Collins and Pat Connaughton to continue contributing through a playoff push. It’s a lot to ask. But Portland’s last several playoff runs have involved juggling a similar number of balls in the air. And with what appears to be a firm foundation on defense for the first time in years, the backcourt only has to make up for the deficiencies of one side of the ball, not two. That may not be enough to give the Blazers much of a shot of getting past Houston or Golden State, but it’s progress just the same.Check out our latest NBA predictions.