Brook Lopez’s more active role on defense in Game 2 helped turn the momentum after Milwaukee’s Game 1 loss.

If there was one play in the Milwaukee Bucks’ 125-91 victory over Atlanta Friday that stood out as a microcosm of the changes from Game 1 to Game 2 of their Eastern Conference championship series, it was the opening possession of the second half.

Of course, given both how big Bucks center Brook Lopez is literally and how big his performance was figuratively, we probably should classify it as a macrocosm of everything that came before and after at Fiserv Forum:

Trae Young, the Hawks’ dynamic young point guard, brought the ball across midcourt against defender Jrue Holiday’s pestering. He briefly got the ball to teammate Bogdan Bogdanovic to release the pressure, then quickly got it back. With about seven seconds left on the shot clock, Young shifted gears and attacked along the left side of the rim.

Enter Lopez, who met him like one of those inflatable wind dancers you see at the used-car lots. Flailing his arms, moving his feet, Lopez bopped in reaction to the elusive Young’s every move. Right down to the baseline, in fact. Then along it to the left corner. And finally up the sideline to the break in the 3-point line.

Atlanta — already down 77-45, already saddled with 13 turnovers worth 22 points to Milwaukee in the first half — came out of the halftime locker room and got stuck with another. The 24-second clock had burped before Young ever got the ball out of his hands.

Despite their mismatch in size and mobility, Lopez hadn’t just stayed with Young. He had stymied him.

“People don’t realize how massive that guy is,” Bucks wing Khris Middleton said. “I mean, he’s a 7-footer but you feel him around when he’s around the rim on the court, even when he’s on the perimeter sometimes. I don’t think people realize how big he is, how athletic he is, how much ground he can cover.”

Said Lopez, “I wanted to make things difficult for him. Try to have hands [up]. And knowing that I had four guys behind me is just so big.”

With Holiday being a pest, Middleton digging from the left as Young dribbled toward the baseline and Giannis Antetokounmpo planted in the restricted area in case Young slipped past Lopez or thought about hoisting a cross-court pass to John Collins on the right side, it was a group effort.

But Lopez sticking with Young was the key. And moments later at the other end, the 33-year-old veteran wrapping up his 13th season poetically hit the sort of floater with which the Hawks’ explosive scorer had tormented him and his team over and over in Game 1.

In the series opener, Lopez looked too often like the family dog on an eight-foot leash with the mailman walking 12 feet away. He was beholden to Milwaukee’s familiar yet often frustrating “drop” defensive coverage, which dictates on screen-and-rolls that the Bucks center stays back, doesn’t “show” on the ball handler and focuses instead of protecting the rim.

The tactic has been a staple of coach Mike Budenholzer’s defense since he arrived three seasons ago, requiring discipline from Lopez and his backups while gambling against mid-range shots vs. layups or lobs at the basket.

It worked well in the first round against Miami, effectively daring Jimmy Butler and Bam Adebayo to hit short jumpers at which they don’t excel. But Brooklyn routinely got to the seam a few feet below the foul line, with undersized center Bruce Brown lofting shots over Lopez so effortlessly that the big man’s viability to stay on the floor got questioned. He was minus-9 for the series, minus-21 in the Bucks’ three losses.

Then came Young Wednesday, with drives into that paint that had Lopez backpedaling to the restricted area. Heck, that deep, Milwaukee’s famous Fonzie statue would have been just as effective as a deterrent. Lopez was minus-14 while playing a mere 20 minutes.

But the Bucks adjusted, both strategically and mentally. They got embarrassed by what looked like a laissez faire performance, casual enough that Young lit them up at home for 48 points and sparked a Hawks comeback from seven points down with four minutes left.

This time, Milwaukee’s defense confronted Young farther out, got physical without fouling (he drew only one foul compared to nine in Game 1) and took Lopez off that short leash.

“He was just active,” Budenholzer said. “And he’s got such a good feel, y’know, in the pick-and-roll defense. He was at his best, and that’s what we need from Brook. He just had great timing, a great understanding of defensive spacing.

“He was just what we see on a lot of nights. I think, try and stay out of his way. Just turn him loose, let him be himself. That’s when he’s at his best.”

It helped that Lopez had his shooting stroke, too, hitting three of five 3-pointers and shooting 6-for-8 overall. He had just one rebound but by eating so much space under the basket, Antetokounmpo, Middleton and PJ Tucker combined to grab 23. Winning that category in Game 2, on top of their 12 steals, demonstrated how much the Bucks dialed up their defense.

Sitting on the bench for the entire final quarter, after a job well done in a blowout victory, had to feel better than sitting for all but 12 seconds of the fourth in Game 1 when it seemed he couldn’t handle the matchups.

“It’s all about activity,” Lopez said, “and that’s definitely a point in the game where I can try to have impact, be someone who can make a difference in the game plan. I definitely enjoy that.”

Steve Aschburner has written about the NBA since 1980. You can e-mail him here, find his archive here and follow him on Twitter.

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