It happened again. Zach LaVine scored a career high 42 points en route to a Bulls 126-116 rout of the Celtics and joined a crowded group of point guards that have lit up Boston like a pinball machine. John Wall, D’Angelo Russell, Devin Booker, Kemba Walker, James Harden, Jamal Murray, and now LaVine have put up 34+ points against their top-5 defense. In many of those games, including last night, they lead to one of Boston’s more confounding losses of the season.

There are many explanations for last night’s dud. After the game, Jaylen Brown said, “we let them get way too comfortable.” In addition to Lavine’s scoring outburst, Lauri Markkanen poured in 35. They combined for 8-for-18 from behind the arc and missed just one of their twelve free throws. Smart wasn’t as dismissive as Brown:

Marcus Smart on what he can pull from past Cs teams that scrapped for everything: "Our toughness. Our will to fight. Our will to do everything. It’s just like, we don’t got the will to do it anymore. I don’t know how you teach effort, will, want-to. I don’t think you can." — Adam Himmelsbach (@AdamHimmelsbach) February 24, 2019

Effort aside, there are some glaring schematic holes in Boston’s defense. LaVine is the prototypical point guard that gives them fits: quick off the dribble, height advantage, and ultra athletic. No doubt, LaVine was on fire in the spots that the Celtics don’t mind giving up buckets from. Here’s his shot chart from the night:

LaVine was 5-for-9 from the long mid-range. Boston will live with that. so many of those shots came on ISO’s and going under screens and dribble hand offs. For the season, LaVine is 37% shooter outside of the key and inside the arc; the league average is 40.3%.

I’ve written about it at length here against the Jazz and here against the Mavericks, but the Celtics’ pick-and-roll defense, particularly above the break, invites shooting performances like this. Because they ICE PnR’s to the sidelines, a shooting pocket opens up when the big retreats off a shooter in favor of defending penetration. Murray hit 5-of-11 threes in his 48-point performance. Harden dropped half of his eighteen triples. Kemba took thirteen and made seven.

Your browser does not support HTML5 video.

Your browser does not support HTML5 video.

However, in the playoffs, this PG defense may not be an issue. The way the seedings are playing out, the Celtics could play some combination of Ben Simmons, D’Angelo Russell, Darren Collison, Kyle Lowry, and Eric Bledsoe. Outside of Russell, none of the East’s elite have a strong scoring point guard. If the Celtics were to make The Finals and face Steph Curry, Klay Thompson, and the Warriors, they’d have to make adjustments to their defense, but we’ve seen them have success against Golden State. In the meantime, these disappointments punctuated by career highs from good players on bad teams will get sprinkled into this frustrating regular season.