The End of "Old Ball Flight Laws"
For decades, golfers were taught that the golf ball starts on the club path and curves relative to the face angle. This is completely false. The ball starts primarily where the face is pointing at impact, and curves away from the path.
In 1999, Theodore Jorgensen published The Physics of Golf, defining the D-Plane (Descriptive Plane). It mathematically proves that ball flight is determined by the 3D wedge created by the club's vector and the clubface's vector at maximum compression.
The Golden Rule of Initial Direction
The ball launches 75% to 85% in the direction of the face angle for irons, and up to 90% for the driver. The path only accounts for the remaining 10-25%.
Example: The Pull-Slice
Path: 6° Out-to-In (-6.0)
Face: 2° Closed (-2.0)
Result: The ball starts left (because the face is closed), but fades massively to the right because the face is 4° OPEN relative to the path.
Spin Axis Tilt
A golf ball does not have "side spin." It has one spin axis. When the face and path do not align, the D-Plane tilts, which tilts the spin axis. A tilted spin axis creates aerodynamic lift that pushes the ball sideways—a curve.
FAQ
- How do I hit a draw?
- The clubface must be closed relative to the club path, but open to the target line.
- Does gear effect alter the D-Plane?
- Yes. An off-center strike on a curved face (like a driver) imparts gear effect, which alters the spin axis independent of the D-Plane's path-face relationship.