Smash Factor could be said to measure the efficiency of transfer of the energy from your swing into the golf ball.
SMASH FACTOR = BALL SPEED / CLUBHEAD SPEED.

So, if your clubhead speed is 100 mph, and you generate a ball speed of 132 mph, you’ve got a smash factor of 1.32.

Make square contact out of the sweet spot and you’ll have a high smash factor. A glancing blow away from the sweet spot will create a lower smash factor.

Understanding the calculation you can see how improving your smash factor will not only add distance, it will likely improve your accuracy. That’s why you should come and get yours measured.