Mark Williams Rebounds Prop is currently Over/Under 7.5 (-120/+112).
The money has been on the Over as it opened 7.5 @ -116 before it was bet up to 7.5 @ -120.
FACTORS THAT FAVOR THE OVER:
The Suns have been the best offensive rebounding offense in the league over the last 5 games (offensive rebounds maintain possession and can therefore lead to additional chances for scoring and assists).
FACTORS THAT FAVOR THE UNDER:
The Suns have played at the 2nd-least up-tempo pace in the league over the last 5 games.
The Celtics have played at the most lethargic tempo in the NBA this year, which should reduce plays for the Suns.