Final game of the regular season between these two. Though Pacers have 8 more Ls in the standings, but the distance in that department could be different. It's real life, so no "ifs".
Pacers vs Celtics 98-108
Pacers vs Celtics 111-112 (we all remember that

Pacers @ celtics 97-91.
Three games, three road victories. A good sign? Not so simple.
Good stuff. Pacers are 100% healthy, with new guy Booker. Last 11 games Pacers are 8-3, two unpleasant road losses, one ugly home L against Utah. Otherwise - all good. Lately Dipo is a little of, but still one of the best SG (or combo guard) in the NBA. Turner is good, Corry the same, Bogie most of the time hitting his shots (that's very good), Domas ehhh (limited minutes look like affecting his usual efficiency and effectiveness). But Domas is a smart dude, no worries here.
Celtics. 6-4 in last ten, only one W against team win winning record - last game at Minny. Convincing W.
Celtics are so overachieving, it's not even funny, but they do deserve it. Exceptional coach, exceptional Kyrie. BUT. All these come back grinding, OT wins are taking the tall. People are not made of steal, some wear and tear accumulates during the season.
Celtics are set in their seeding position, but for Pacers every game is utmost important. Pacers have a rough schedule, though having a full, healthy roster is huge this time of the year.
Conclusion. Though Celts are 6.5 favorite, in my book it's 50/50.
So, boys and girls, let's get that W and move one. Third or fourth place to finish he season is open, home court advantage during the first round is priceless for this young and fun team.