Monday, May 08, 2006


It's a Very Simple Game?

The late Baltimore sports commentator Charley Eckman used to say "It's a very simple game." Apparently, that's not necessarily the case.

A recent study, "Scattering of a Baseball by a Bat," concludes:
A ball can be hit faster if it is projected without spin but it can be hit farther if it is projected with backspin. Measurements are presented in this paper of the tradeoff between speed and spin for a baseball impacting a baseball bat. The results are inconsistent with a collision model in which the ball rolls off the bat and instead imply tangential compliance in the ball, the bat, or both. If the results are extrapolated to the higher speeds that are typical of the game of baseball, they suggest that a curveball can be hit with greater backspin than a fastball, but by an amount that is less than would be the case in the absence of tangential compliance.
Theoretically, then, if you can hit a curve ball, it will travel further than a similarly hit fastball. This presumably increases the likelihood of the batter hitting a home run. However, a hit fastball will move with greater speed. One would think that this would thus increase the number of hits "through the hole" in the infield. However, the authors warn:
These results will have implications for the issue of whether an optimally hit curveball will travel farther than an optimally hit fastball. To investigate this in detail requires a calculation of the trajectory of a hit baseball . . . . Such a calculation requires knowledge of the lift and drag forces on a spinning baseball. However, given the current controversy about these forces, further speculation on this issue is beyond the scope of the present work.
Hat Tip: ResourceShelf's DocuTicker.

2 comments:

Daryl Sidle said...

Stu:

If you really want proof that it is not a simple game, check out the book, The Physics of Baseball, by Robert Adair;he is at Yale.

You'll get all kinds of neat things on the flight of a baseball, including how the stiches on a ball effect resistance and things like the Magnus coefficient.

To me, this is what great science writing is all about. It is not about taking something very complex (like relativity or string theory) and showing that it is really simple (it ain't). It is about taking something that looks very simple (like hitting a baseball or explaining why the sky is blue) and showing how truly complex the phenomenon is.

Thanks for the cite.

Anonymous said...

You think hitting a baseball is hard. You should have tried scoring with Ruthie Weinglass in junior high. Had to go down low in a bunting crouch and stick my bad straight out.

I whiffed.