Almost never is an NBA game decided by halftime. This one was. A best-of-seven series cannot be decided after two games. This one feels close to done, though.

Three seconds before halftime in Wednesday’s Game 2, the Hawks trailed by 38 points. They’d scored 36. The Cavaliers had more than doubled the score against the NBA’s second-best team in defensive efficiency. That’s insane. But it showed how crazy good Cleveland can be — and how overmatched these Hawks appear.

The Cavs made 18 3-point shots in the first half. The previous playoff high in a half was 12. They obliterated it. In the process, they obliterated the Hawks. (The Cavs would finish with 25 treys, the most in any NBA game ever. The Hawks made 30 baskets.)

Afterward, Al Horford was asked if the Hawks could still make a series of this. “That’s a big question for us right now,” he said, not exactly offering a big answer. “We had a game plan we thought was really good. It got discarded.”

Seven Cavaliers made treys in the first 24 minutes. Cleveland made 18 of 27 3-pointers in that half, which is 66.7 percent, which is nuts, but here’s the wild part — the Cavs had missed 15 of 21 2-pointers. They’d made 28.6 percent of the shorter shots. It mattered not one whit.

As the clock wound down in the second quarter, the Cavs spread the floor. You knew they’d hoist a 3-pointer because why the heck not? They’d sailed home so many outrageous treys that the whole thing had gotten silly, and the Cavs on the bench — LeBron James chief among them — were standing and positioning themselves to react long before the ball came to Kevin Love in the right corner. He rose and sank Trey No. 18.

As the Hawks were inbounding, the Cavs were acting as if they’d won the series. Certainly nothing this night suggested a reversal is imminent. They led by 18 in Monday’s Game 1 before Dennis Schroder made it interesting, but nothing in Game 2 was interesting about the visitors. They scored only 38 points in the half, 16 of those by Paul Millsap. Schroder was chased off the court after six minutes, one missed shot and one turnover.

After Game 1, the Hawks maintained they were encouraged at having come so close, although technically they lost by 11 points. They opened Game 2 by trying to feed Kyle Korver, who hadn’t made a basket Monday. Sure enough he scored the first hoop. But it was a 2-pointer, not a trey. He would finish the half with four points. He took only one 3-pointer. It missed. When finally he made a trey, it cut the Hawks’ deficit from 41 to 38.

We Atlantans saw J.R. Smith torch the Hawks in Game 1 of the Eastern Conference finals last season, but this was special even by his freakish standards. He made a trey in the first quarter off a LeBron feed that might have touched Smith’s hands for 0.2 seconds. His fallaway 3-pointer made the score 35-20 at quarter’s end. He hit another over Al Horford — again a non-factor this first half — and then lost Korver with a behind-the-back dribble for the hoop that made it 66-36 and sent the frothing crowd at Quicken Loans Arena into stark raving rapture.

They Hawks were loose with the ball early, the Cavs were ruthless in their efficiency. They scored 20 points off the Hawks’ first eight turnovers — six 3-pointers and two free throws. That also beggars belief.

The Cavs had 74 points at the half. The Hawks had 70 after three quarters. Remember how they said they felt better prepared for LeBron & Co. this time? After this embarrassment, we have to ask: How might unprepared look? Forget guarding LeBron. (Nobody guards LeBron.) The Hawks don’t look as if they can guard anybody. Cleveland scored its 100th point with 3:51 remaining — in the third quarter.

It got so bad that Mike Budenholzer ordered his team into a zone late in the second quarter, which seemed counter-intuitive: Why give a team that’s making every 3-point shot an invitation to take another? (But hey, nothing else was working.)

On cue, the Cavaliers worked the ball around the horn to Kyrie Irving in the right corner. He hoisted a trey. It swished. But of course.