Skip to main content

Reply to "Pitching anomaly"

Whether it spins clockwise or counter-clockwise depends on which side of the pitcher you're standing on when you look at it!

The 4-seam spin tends to stay straighter because the seams are evenly spaced and so the impact of seams on air is uniform through rotation. With a 2-seamer, the seams hit the directional path with uneven spacing. The ball can develop a "wobble" that enhances the movement. Kind of like driving your car with one of the two front tires under inflated -- you'll feel a pull to the drag side.

As for the physics explanation for decreased velocity on the 2-seamer:

If you're into vectors, when the 2-seamer starts to tail or run or sink, most of the velocity remains on the vector pointing directly to the plate, but some of the momentum bleeds off into a vector heading left, right or down. With a 4-seamer there is less of that effect and so the vector towards home retains more of the initial forward momentum (or "muzzle velocity" if you prefer).

By the way, the potential for a fastball to rise is a topic that generates its own believers and non-believers. I happen to be a believer. But the physics explanation for the rising fastball has little to do with the seams and all to do with the spin, rotational velocity, and what your physics professor would call "dipole moment". After all, a billiard ball or a bowling ball (smoothly surfaced spheres) will travel a curved path if spun with "English".
×
×
×
×