Coefficient of Restitution (COR)

Coefficient of Restitution (COR) quantifies the efficiency of a collision. In golf, this relates to the energy transfer when a clubface impacts the golf ball. A clubface with a higher COR correlates to less energy loss and more potential distance.

While COR is a technical measurement used by club manufacturers, its impact on performance is one that can be instantly felt by golfers. The higher a club’s COR, the farther a player will be able to hit the ball.

A “perfect” collision has a COR of 1. However, the laws of physics make this unattainable due to inevitable energy losses. Additionally, the USGA imposes a COR performance restriction at 0.830. This ensures all clubmakers are working toward the same maximum limit.

An optimized COR translates to noticeable ball speed gains, making it a top priority in Titleist’s club development process. Considering the COR can change across the surface of the clubface, we focus on getting as close to the 0.830 maximum at every point of the face—not just the center.

Achieving this demands design ingenuity and rigorous testing to deliver best-in-class distance without compromising ball flight, consistency, stability Moment of Inertia (MOI), and durability.