Moment of inertia
Moment of Inertia (Moi)
The resistance to twisting of any golf club head when that head is impacted off-center.
At the moment of inertia (MOI), the power and momentum that you have built up with proper balance and timing in your golf swing in the way of club head speed is transferred to the golf ball.
M.O.I.: Moment of Inertia The resistance to twisting that a clubhead displays at the moment it strikes the ball. A clubhead with a higher moment of inertia will twist less and offer more forgiveness on off-center hits.
By distributing an object's mass toward the outer boundaries, it increases the Moment of Inertia, (MOI) which in golf makes the club less resistant to twisting on off-centre hits and hence more forgiving.
Golf Clubs FAQ
Moment of inertia, COR, center of gravity, gear effect ... what does it all mean? Check out the Golf Clubs FAQ.
Swing weight is a measure of a club's moment of inertia around a pivot point 14 inches from the grip end of the club.
Putters with a high MOI, or Moment Of Inertia, provide added forgiveness due to extreme perimeter weighting and an enlarged sweet spot.
Why Do I Miss So Many Short Putts? You're taking the club too far inside or outside.
The scientific label for this is "higher moment of inertia". Clubs with larger heads, be they woods, irons or putters, will not twist as much when you don't hit them perfect, resulting in straighter - and longer - shots.
For that reason it can be the most inaccurate of the clubs, although larger head sizes and higher moment of inertia have helped to make drivers more 'forgiving'. Some of the top professionals can regularly drive the ball over 300 yards.
swing weight the relative weight of a clubhead's leverage (usually measured on a scale with a 12 or 14-inch fulcrum), technically - moment of inertia, or the tendency of a body to resist angular acceleration; ...
See also: Shaft, Golf, Impact, Swing, Shot