The Bucks matched up poorly against the Heat. Perhaps also distracted by spearheading a one-game boycott, the Bucks were drummed out of the playoffs by Miami.
Credit to the Heat. But now Miami draws a well-focused opponent it doesn't match up well against. The Heat might have grabbed Game 1 in this series with a situational advantage since they are rested while the Celtics had to go the full seven games to eliminate the Raptors.
However, the NBA schedulemakers negated that edge for Miami by scheduling this game four days after Boston took out Toronto. That's enough time for the Celtics to rest, recuperate and fully game-plan for Miami. The Heat, on the other hand, last played a full week ago. So they have to deal with a rust factor and lost momentum.
The Heat finished 12th in defensive efficiency during the regular season. They stepped up defensively against the Bucks. They did that by keying on Giannis Antetokounmpo and gambling that the rest of the Bucks weren't good enough. That worked because the Bucks weren't the same team inside the bubble they were during their dominant regular season when they won 53 of their first 63 games.
The Bucks lacked off-the-dribble threats aside from Antetokounmpo. The Celtics have a different makeup. They don't have one superstar. Instead they have several stars - Kemba Walker, Jaylen Brown and Jayson Tatum - a strong bench and the best coach in the league, Brad Stevens.
The Celtics actually are going to find scoring easier against the Heat than they did against the Raptors, who had the No. 1 defense in the league. The Celtics are vulnerable to fast backcourts and teams who have multiple shot creators. Aside from Jimmy Butler, the Heat don't have that, nor can they match Boston's trio of star power. The Celtics have the needed defensive flexibility, too, that Milwaukee lacked. The Celtics can play up-tempo if it suits their purpose, or handle a half-court game that Miami favors.
Prior to this season, the Heat hadn't won a playoff series since 2016. They lack the necessary deep playoff pedigree that Boston has from reaching the conference finals in 2017 and 2018.
Upsetting the flawed Bucks has made the Heat overvalued. The money line price is low enough to back the superior Celtics.