Why Are Celtics Worse When Marcus Smart Shoots Better? Bizarre Stat Explained

Marcus Smart was on his game Monday night, tallying a season-high 23 points on 61.5 percent shooting (8-for-13).

Which, it turns out, is bad news for the Boston Celtics.

The Celtics lost for just the fourth time this season, falling to the Detroit Pistons 118-108 at TD Garden despite Smart’s best efforts. But this isn’t the first time they’ve failed while Smart has succeeded. Check out this crazy stat from ESPN’s Chris Forsberg:

That’s right: The Celtics have won every game in which Smart has been atrocious offensively. (The league average shooting percentage was 45.6 entering Tuesday). And the young guard has shot well (by his standards) in all four of Boston’s losses to date.

How the heck does that make sense? Shouldn’t the C’s perform better when one of their most important role players is hitting his shots?

Such is the conundrum presented by Smart, a ferocious defender and historically awful shooter who can have a massive impact on games despite hoisting a steady stream of bricks.

Take Boston’s signature win over the Golden State Warriors on Nov. 16. Smart had his worst shooting game of the season, scoring one point on 0-for-7 shooting, but the C’s outscored Golden State by 15 points when he was on the court, thanks to plays like this:

This trend isn’t an anomaly, either: Smart is a 34.7 percent career shooter in Celtics wins and a 36.1 percent career shooter in losses. In two of Boston’s most lopsided victories this season, he shot zero (!) percent (0-for-3 in a 27-point win over the Sacramento Kings) and 14.3 percent (1-for-7 in a 15-point win over the Orlando Magic).

How do we explain this?

Here’s the most plausible theory: Scoring isn’t Smart’s primary job, so when the Celtics are relying on him for buckets, it means they’re in trouble. Boston has a multitude of scoring options — Kyrie Irving, Jaylen Brown, Jayson Tatum, Al Horford and Marcus Morris all average double figures — which usually can mask Smart’s offensive deficiencies and allow him to do what he does best: Dish out assists, wreak absolute havoc defensively and make mind-boggling hustle plays.

There’s an interesting twist to that theory, though: Smart actually shoots better with the game on the line. The 23-year-old is shooting 37.8 percent from the floor this season when Boston is leading or trailing by five points or fewer, his highest of any score margin split. (When the C’s lead or trail by 20 or more, that number plummets to 14.3 percent).

Celtics fans watching Monday night’s game can attest to that: Smart drilled a trio of clutch 3-pointers in the fourth quarter to help keep the C’s in the game.

Smart’s success in the clutch only confirms our original theory, though. The rest of Boston’s offense struggled mightily around Smart in the fourth quarter, contributing 13 total points on just 3-of-12 shooting as the Pistons pulled away for good.

In essence, Smart’s at his best doing the Celtics’ dirty work while the likes of Irving, Brown and Tatum dazzle offensively. But make no mistake: He’s a big reason why Boston owns the NBA’s best record.

“(Smart is) a guy that figures out ways to win,” C’s coach Brad Stevens said recently. “Sometimes you can look at that conventionally and other times not. There’s a reason he’s in the game when the game is on the line.”

Just don’t let him top that 30 percent mark.