After the Hawks made a postseason team record 20 3-point shots to eke out a Game 1 victory over Philadelphia on Sunday, the formula for staging an upset in this series was clear. Just shoot out of your mind, shoot like the rim was 10 feet wide, make ‘em in unheard-of numbers, and anything is possible.

Realists suspected that might be an undependable strategy. “I hope we don’t need to hit 20 moving forward in the series, but when you shoot like that, you give yourself a pretty good chance to win,” said one of the Hawks’ shooters, Kevin Huerter, at the time.

That thud you heard was, first of all, the sound of the off-center 3 against unforgiving metal. Second, it was the noise the Hawks made in losing at home for the first time in 14 games Friday, falling to the 76ers 127-111 and falling into a 2-1 series hole.

After making the 20 treys in Game 1, the Hawks have totaled 17 in games 2 and 3. They are on a course of diminishing returns. On Friday they were just 6-of-23 from extra-credit range, after going 11-of-30 in Game 2.

As teams are wont to do in these condensed series, Philadelphia responded to the first-game assault and adjusted. The Hawks’ Bogdan Bogdanovic has noted the Sixers defenders are doing a much better job of denying kick-out passes to the Hawks’ shooters. Hawks interim coach Nate McMillan said Philly, a proud defensive team, has begun “doing a solid job of staying in front of us.” And they are staying in front of Hawks shooters with troublesome, long-limbed defenders. Hard to see the 3s for the trees.

More than that, McMillan said, look to the Sixers’ success on offense for this recent ability to contain the Hawks’ shooters. Philadelphia got to the rim effectively and as a result shot 53% from the field Friday, giving the Hawks fewer opportunities to run out after misses and line up favorable shots for themselves.

“We have to get more ball movement. We have to set better screens to try to free up the basketball,” he said. “But it really starts on the defensive end of the floor, though.

“We got to get stops so we can try to get out into transition and get some easy baskets and not play against a set defense for the majority of the game. That’s where it starts for us.”

Hawks guard Trae Young took 11 3′s in that Game 1 victory, but squeezed off only six Friday (making half of them). A shooter always believes the next shot is going to fall, and that seemed to be the mindset he carried out of State Farm Arena on Friday night.

Asked if he was surprised or concerned by the fall-off in the Hawks’ shooting, Young answered, “I’m never concerned. This team, these guys have worked too hard to feel down about their shot. I’m not down or worried about guys’ shots. They’re going to fall eventually, I know they will. We got to keep shooting them, keep playing with confidence out there.”

The 3-point shot is the equalizer upon which the Hawks must rely against a team like Philly. The 3-point shot gives the Hawks a puncher’s chance against a bigger bunch that has used that size so effectively on both ends of the floor to win the past two games by double digits.

But the puncher has to get back his punch.