Rebound Percentage (REB%) estimates the fraction of available rebounds a player grabs while on the floor, combining offensive (ORB%) and defensive (DRB%) components. It normalizes raw rebound totals for pace, teammates' rebounding, and the number of shots taken while the player is on the court.
Rate-based rather than counting-based — directly comparable across eras and players with different minutes. Captures both offensive and defensive rebounding contribution in a single number.
Measures rate of rebound grabbing, not the value of individual rebounds. A team's rebounding depends significantly on defensive scheme (some teams intentionally concede offensive rebounds to prevent transition baskets). High REB% in a center is partly a reflection of playing time distribution among teammates.
REB% is the sole metric in APEX's Versatility pillar (8% total weight). It was retained in v1.7 after STL% and BLK% were removed following Jewell et al.'s finding that those metrics showed null significance at high minutes loads. REB% at 8% contributes modest signal about a player's physical versatility contribution. It is intentionally the lowest-weighted pillar in APEX, reflecting the model's position that rebounding is a real but secondary contribution relative to impact, scoring efficiency, defense, and playmaking.