Impact and Ball Flight
a Driver's Launch Parameters
lot of clubfitters use launch monitors now to fit the driver to the
golfer. A common scenario is to get to a fast maximum, but one that
doesn't match the spin and launch angle numbers that are supposed to be
optimum. This is followed by tinkering to get to the optimum launch
conditions -- usually with little or no additional distance to show for
it. Here is why that happens, and what to do about
Matters for Driving Distance?
Schotman has observed that, statistically from current PGA Tour data,
ball speed is a significant factor in driving distance, but launch
angle and spin are somwhere between insignificant and zero. Here we
explore why this should be.
Position for Maximum Distance
ways to increase driving distance are to hit up on the ball (increase
the Angle of Attack) and to hit the ball higher on the clubface. Key to
both is the proper ball position. The ball must be positioned further
forward in the stance and teed higher. This article covers how much
forward and how much higher.
Comparison of Trajectory Programs
mini-study was provoked by response to my study of launch space
surfaces, and my driver fitting recommendations based on that study.
The accuracy of the Tom Wishon Trajectory Profiler was called into
question. Here I compare the Wishon program to three others, and to
measured, real-world data.
There is a common diagram in many golf books that purports to show the
nine basic ball flights. Unfortunately, that diagram is somewhere
between useless and incorrect. Here is a version (actually two
versions) of the diagram that correspond to physical reality.
Slice and Hook
big a slice or hook will you get from a particular amount of open or
shut in the clubface? Here is a way of estimating it, that could even
be used on the golf course for precision in working the ball.
effect occurs when a driver strikes the ball, and the impact misses the
sweet spot. The result is a rotation of the clubhead that imparts spin
to the ball. It answers all kinds of questions, like: why woods are
designed with curved faces... why weight screws may (or may
give a hook bias... why a driver gives maximum distance when
above center on the clubface. I was surprised by a few of the answers
Newton and the Divot
Not many people seem to be aware that the clubhead is deflected
downward at impact. The physics is pretty easy, but the fact is
obscure. It is a partial explanation of why your clubs have to take a
Smash Factor - Myths and Facts
Is the maximum possible smash factor 1.5? Sort of. Sometimes. It
depends. Specifically, it depends on the characteristics of the club
you use, and not just how well the ball is struck.
Spin Decay for a Ball in Flight
How fast does a spinning golf ball lose its spin in flight?
Launch Conditions from Impact Conditions
from impact conditions to launch conditions is a challenge.
It's even harder in 3D. Here's my cut at how to do it.
warning! Most of this article consists of deriving equations for launch
conditions, and is heavy with trigonometry.)