The setup the Celtics have now worked for them. Brown is the main scorer and Tatum is the secondary scorer. If Tatum attacks, he would easily attract the defense; sometimes he'll get double-teamed, so he could just pass the ball, and with good ball movement, they'll be able to find an open man. The 3-point shooting in game 1 was very good, though not so impressive, but just enough to dominate Dallas.
This is the reason why Brown looks like stepping but no one notice he always has space created by Tatum that’s why he can score easily. It’s working because Brown is not choking unlike previous years when they still have Smart which always choke on the finals.
With the new Boston line-up, Tatum doesn’t need to do the heavy lifting all time but rather trust to his teammates to score in his place.
Usually, game 1 is a surprise by the home team, and that's just what happened. But now we are going into game 2. Will we see the same outcome, or are you expecting Dallas to even the series?
I really doubt Dallas can easily cope with that overwhelming defeat but they can even the series if Kyrie will explode together with Luka because this can answer Boston aggression.