I am not going to make a definitive prediction on the game but my feeling is that the Celtics will have balanced scoring, no one player is going to "go off". Tatum and Brown will be 20 points or so. Smart and Horford in the 15 range. White, Grant, Rob, Pritchard will all pitch in something meaningful.
I was sorting through some stats and I found an interesting sort on Jaylen Brown. In the 4th quarter, in the first 5 games of this series, Jaylen Brown is shooting 81% overall and 82% from 3. He leads the team with 9.8 pts per game in the 4th.
Theis 67% (and not all garbage time), Smart (67%), and Horford (60%) are also killing it in the 4th. Pritchard is the second highest scorer in the 4th with 5.3 pts per game. Daniel Theis is averaging more minutes (6.1) and more points (2.3) in the 4th than RWill (5.7 min/0.5 pts). RWill has only played in the 4th in 2 games and it appears that he is wearing down.