By Staff
Coaching Management, 9.1, February 2001, http://www.momentummedia.com/articles/cm/cm0901/bbcollision.htm
For years, many batting coaches have encouraged their players to loosen their grip on the bat while swinging—and a recent study conducted by Alan Nathan, physics professor at the University of Illinois, provides some hard data to back up that philosophy.
Nathan’s “Dynamics of the Baseball-Bat Collision,” published in the November, 2000 issue of the American Journal of Physics, looks at what happens when the ball is struck by a standard wood bat (in this case, a 33-inch, 31-oz Louisville Slugger R161). According to Nathan, exit speed of a batted ball is determined by only a small region of the bat barrel. The handle of the bat is far enough away from the barrel that it won’t transfer momentum to the ball when it is struck. “The ball doesn’t know that the far end of the bat is there,” Nathan writes.
“The handle of the bat has barely started to react to the impulse by the time the momentum transferred is complete and that any clamping action of the hands will affect the bat at impact point only after the ball and bat have separated,” Nathan concludes in the study’s summary. “From this we have concluded that the exit speed of the ball is essentially independent of the detailed size, shape, and method of support of the bat at distances far removed from the impact location.”
What does this mean for coaches? Well, if you’re from the relaxed-grip school of batting instruction, you can keep on giving the same advice. If you’re not, you might try doing what many successful hitters have figured on their own when it comes to their batting grip: loosen up.
Nathan’s article, as well as others relating to the physics of baseball, can be found on his Web site at: http://www.npl.uiuc.edu/~a-nathan/pob/index.html.