# What Does COR Mean In Golf?

A phrase that has become a common one in golf, we explain the exact meaning here.

COR is still used to measure fairways, hybrids and irons

A phrase that has become a common one in golf, we explain the exact meaning here.

What Does COR Mean In Golf?

A term that is not out of place in a conversation with Bryson DeChambeau, COR is an acronym that has fast become a normal part of golf's language and it means the 'Coefficient of Restitution.'

What does that actually mean?

The coefficient of restitution is basically a term that describes energy transferred between two objects.

The COR figure for Object A is a measurement of Object A's ability to transfer energy to Object B when the two collide. So in terms of golf, A is the golf club and B is the golf ball.

The figure generated is between 0.000 which signifies all the energy has been lost, and 1.000 which signifies all the energy has been transferred. The perfect 1.000 figure is impossible because the club and ball are made from different materials and have different weights. Sir Isaac Newton developed the mathematics to COR back in the 17th century.

Usually a higher COR means more distance which explains why there are limits on it. Back in the 90s and 2000's there were no limits and with the introduction of ultra-thin, springy faces on drivers in particular, the distance players could hit the ball could only go up and arguably get out of hand. Therefore a limit was introduced by the powers that be.

As of right now the current limit on COR is 0.830 which means 83% of the energy from the club face is transferred into the ball. Anything that goes over that is ruled non-conforming.

It should be acknowledged though that the USGA and R&A do not use COR as a measurement to measure drivers anymore, they instead use CT or 'characteristic time'. COR is still used to measure fairways, hybrids and irons though and club manufacturers are constantly looking for new ways to make the energy transfer from club to ball more efficient.

For more gear content, do not forget to follow Golf Monthly on Facebook, Twitter and Instagram.