Smash Factor

What is Smash factor?

The Smash factor is the ratio between ball speed and club head speed. 

Technically smash factor give us how centered and solid of our shot. this parameter is important to take into consideration, especially amateurs that try to swing to hard at the ball, but they lose control and can not get a solid or centered impact, hence obtaining a low smash factor.

Example: 

A club speed of 100mph and smash factor of 1,40 = ball speed of 140mph

However increasing the smash factor with a more controlled swing, lowering the club speed the result can turn into more ball speed therefore increase the distance.

Example:

A smash factor of 1,48 with lower club speed of 98mph generates a ball speed of 145mph.

Since 1mph ball speed gives 2 more yards of carry, 5mph of difference means 10 more yards to the shot.

There are a maximum obtainable smash factor assuming a dead-centered hit determined by 3 factors:

• Coefficient of restitution between club and ball (COR of 2 colliding objects is value representing the ratio of speed after and before the impact. USGA have limited this ratio for clubs and balls to a maximum of 0,83)
• Spin loft (angle between club face orientation and club head direction)
• Mass ratio between ball weight and club height

Here it is the equation for the maximum obtainable smash factor.So depending of the maximum ratios permuted by regulations (COR=0,83; Spin Loft= 8deg; mass ratio= ball mass 45g / driver head 212g) the maximum smash factor would be 1,494

What is a good smash factor?

Depends on the club and the ball type. For a driver with premium ball, an amateur would obtain 1,42. Tour pros should aim not less than 1,48 as minimum.

Here are some tables with data and observations with professional players.

All this information was extracted from Trackman.