Al Horford Rebounds Prop is currently Over/Under 4.5 (+104/-134).
The money has been on the Under as it opened 4.5 @ -124 before it was bet down to 4.5 @ -134.
FACTORS THAT FAVOR THE OVER:
Offensive rebounds lengthen possession and bring about more opportunities for scoring and assists, and the Warriors rank 5th-best in in the league with 12.2 offensive rebounds per game since the start of last season.