Marcus Smart's 3-point shooting took down the Cavaliers. That's a literal miracle

Marcus Smart is a bad three-point shooter. He was a bad three-point shooter at Oklahoma State, where he never eclipsed 30 percent in either of his two seasons. He’s been bad in his three seasons with the Celtics, where his 29.1 percent career number is just decimal points away from what it was at OSU.

And yet! Here was Marcus Smart on Sunday night, launching up 10 triples and knocking down seven of them in Game 3 of the Eastern Conference Finals against the Cavaliers. Smart also got fouled on a three-pointer with 1:19 to play, and the two (of three) foul shots he made after that turned out to be critical. Smart scored 27 points to lead Boston to a stunning comeback win, sealed at the buzzer by Avery Bradley. Almost all of those came via the three, and all of those makes came from 23 to 25 feet out.

When a 29 percent three-point shooter clicks at 70 percent to take down the best team in the conference in a game like this, it’s obviously a shock. But what Smart did was really incredible. It also might never happen again — at least not in a situation like this one. This was a basketball lightning strike.

Smart had hit seven threes exactly one other time.

That was in his rookie season, 2014-15, when he went 7-of-12 in a March loss to the Thunder. He didn’t make more than four in any other game that season and didn’t make more than five in a game in either of the last two.

In Smart’s career, he’s played in 233 regular season or playoff games. He’s made this many triples in less than 0.9 percent of those games.

Percentage-wise, this was right at the top of Smart’s career, too.

Smart sometimes gets hot, like all shooters do. But he’s never had a game even approaching this level of three-point excellence. If you filter for only games in which Smart shot from deep five times or more, you only get nine regular season (and zero other playoff) games where he shot 60 percent or better from deep.

He’d never made more than 50 percent of five or more threes in a playoff game in his career. There had not been a single playoff game in Smart’s career where an apt takeaway from the night had been, “Wow, Smart sure shot it well from deep tonight.”

Some context on how miserable Smart’s been on threes, in general:

This is probably never going to happen in a moment like this one again.

That’s not a criticism, either. That Smart did this to LeBron James and the Cavaliers is awesome, and it’s so cool that these predictable NBA playoffs got a dose of unpredictability. If the Celtics pull a miracle comeback — and it’d still be a miracle, for sure — the time Smart did something he’d never done will go down in Boston lore.

But if the Celtics are to steal another game from the Cavs, the best bet is that it won’t come on a night when Marcus Smart puts up double-digit three-point attempts.