Kyrie Irving, Celtics Dominate Giannis, Bucks for Game 1 Upset in NBA Playoffs

Some were skeptical that the Boston Celtics could carry over their momentum from Round 1. The theory went that the Indiana Pacers were so battered that the Celtics essentially had a walkover and would get a rude awakening once they made the trip to Milwaukee.  

Whoops.

Kyrie Irving had 26 points and 11 assists, and Al Horford was a two-way marvel as the Celtics earned a 112-90 win over the Bucks in Game 1 of their second-round series.

The Celtics led by as many as 15 points in the first half before the Bucks went on a run before the break to go into the locker room down two. But rather than fold in the face of a raucous Milwaukee crowd, Boston came out of the locker room firing and destroyed the Bucks in a 36-21 third quarter.

The Celtics shot 54.0 percent from the floor and had five players in double figures. Horford was without question the Game MVP, finishing with 20 points, 11 rebounds and three blocks while playing sterling defense on Giannis Antetokounmpo.

The presumptive MVP finished with 22 points on 7-of-21 shooting in by far his worst performance of the postseason.

Al Horford Is Celtics' Most Important Player

What a virtuoso performance from Horford, the perpetually underrated cog that makes the Celtics machine go. Those who have failed to appreciate the quiet brilliance of Horford's game got a firsthand look at why he's the key to the series.

With his arms spread wide and his feet shuffling ably alongside Giannis, Horford gave the NBA MVP fits. No one can stop Giannis outright; he's far too gifted. Even a bad game saw him put up 22 points and eight rebounds through the sheer force of his will. But Horford makes it just difficult enough to throw off the Bucks' offensive ecosystem.

Perhaps even more troubling was Horford's work on the offensive end, which might result in a defensive adjustment for Milwaukee in Game 2. The Bucks employ a drop-down defensive system, which means their bigs go under pick-and-rolls in an attempt to clog the lane. That strategy was basketball death against Horford in Game 1, who knocked down three threes and consistently made the Bucks pay for their decision to let him shoot.

If Horford keeps knocking down those shots, Mike Budenholzer is going to have to adjust, which will probably create some rotational changes. Brook Lopez isn't fleet-footed enough to chase on the pick-and-roll, and Ersan Ilyasova would also struggle to keep up. That could mean more minutes for Nikola Mirotic, himself not the most fleet of foot, or even force Giannis into playing extended minutes at the 5.

Please note that "most important" does not necessarily mean best. Irving remains the Celtics' best player. For this series, though, the Celtics are going as far as Horford takes them. 

Giannis Needs to Work More As Facilitator for Bucks to Advance

The Bucks also need an adjustment from their best player, who will need to take on a more facilitative approach in this series. Bully ball isn't going to work against Horford and Aron Baynes; they're too big and rangy. 

Giannis has to do a better job of finding his teammates on drives, particularly once he gets a step on Horford or Baynes. He finished with just two assists in Game 1, a result of him attempting to barrel to the basket with his head down and force up tough shots. It was borderline Westbrookian at times—and not in a complimentary way.

The Celtics are sending help down when Giannis gets a head of steam, and the Bucks can find open shots out of those if Giannis makes the pass.

On the bright side: Giannis knocked down three threes. Those came mostly because the Celtics are handing him the shot on a wide-open platter and daring him to take it, but they're going to have to adjust themselves if those jumpers keep falling.

Perhaps more than any other second-round series, this will be a chess match of adjustments and adjustments to those adjustments. 

Giannis hasn't had more than four assists in a game during the playoffs after averaging nearly six per game during the regular season. He needs to do a better job of utilizing his vision and passing ability or the Celtics will be able to zero in on him to the point of destroying Milwaukee's half-court sets. 

What's Next?

The Celtics and Bucks reconvene in Milwaukee for Game 2 on Tuesday night.