Kevin Pelton at ESPN thinks the Pistons have the third highest probability of all the first round series. Pelton looked at "the historical odds of winning a playoff series based on the two teams' point differential during the regular season along with the results of the head-to-head season series" and here is the relevant write up on the Pistons:
The Pistons' chances are inflated slightly by winning the regular-season finale between the two teams, who both rested their starters. Detroit outlasting a 36-point effort from Jordan McRae doesn't really tell us much about what the playoff series will look like.
Nonetheless, the Pistons won a pair of more competitive games against the Cavaliers, including a 96-88 victory in the only game with midseason addition Tobias Harris in the lineup.
Harris, Marcus Morris and Stanley Johnson give Detroit a variety of athletic forwards with enough size to defend LeBron James, who went 5-of-18 with six turnovers in the February matchup. Cleveland is still the sizable favorite, but this could be a relatively tricky 1-8 matchup.
Upset probability: 28 percent
According to Vegas odds, the Pistons have 4-1 odds to upset the Cavs in the first round.
H/T to Mannie32 for sharing the link in the comments.