Knuckleball
Almost no spin, so the seams and the air decide.
A Knuckleball flying to home plate in 3D, from the catcher's view.
What it does
A knuckleball is pushed out with hardly any spin. Without spin there is no steady Magnus force; small differences in the air around the seams make a real knuckleball flutter unpredictably.
How to read it
You can see the seams, almost standing still. That is the cue. It is slow, so wait, and expect it to move late in a direction nobody can call.
What makes it work
Killing the spin is the whole skill. AXIS43 shows its average path; the flutter itself comes from seam effects this model does not predict.
The numbers
| Speed at release | 48 mph |
|---|---|
| Speed at the plate | 42.8 mph |
| Time to the plate | 0.57 s |
| Spin rate | 90 rpm |
| Break direction (clock) | 6:00 |
| Spin efficiency | 100% |
| Movement from spin, up or down | 2.0 in down |
| Movement from spin, sideways | 0 in |
| Total drop with gravity | 66.1 in |
A typical Knuckleball from a right-handed pitcher at 43 feet in still air, from the AXIS43 flight model. A physics estimate, not a radar reading.