What Does COR Mean In Golf?

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

What Does COR Mean
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.

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Sam Tremlett
Senior Staff Writer

A golfer for most of his life, Sam is a Senior Staff Writer for Golf Monthly. 

Working with golf gear and equipment over the last five years, Sam has quickly built outstanding knowledge and expertise on golf products ranging from drivers, to balls, to shoes. 

He also loves to test golf apparel especially if it a piece that can be used just about anywhere!

As a result he has always been the one family and friends come to for buying advice and tips.

He is a graduate of Swansea University where he studied History and American Studies, and he has been a part of the Golf Monthly team since December 2017. He also previously worked for World Soccer and Rugby World magazines.

Sam now spends most of his time testing and looking after golf gear content for the website. He also oversees all Tour player content as well. 

Unfortunately, Sam is not a member of any club at the moment but regularly gets out on the golf course to keep up the facade of having a handicap of five.