Posted by: Deano (dharisis@firstam.com) on Fri Dec 13 08:16:35 2002

There must be a math formula on bat speed increase and decrease with bat lenght and weight. Problem: With force constant (the swing), what is the change in bat speed with diferent bats. Bat 34in. 31oz.; bat 34in. 29oz.; bat 33in. 30oz.; bat 32in. 29oz. One formula that comes to mind is F=MA (Force = mass times exceleration). With the Force constant and the mass decreasing the exceleration increases. But added to the mix is that the shorter the bat the slower the sweet spot travels. Any help on this concept.
> >
> > Read Robert Adair's "The Physics of Baseball". It will be one of
> the best $10 paperbacks on baseball you'll ever read.
> >
> > He goes into great length about this subject, and even proves that heavier bats (more mass) do in fact result in longer trajectories for batted balls. I can't quote with certainty what he details, but there is some offsetting that occurs when a heavier bat tries to
> compensate for any (implied) reduction in bat speed.
> >
> > Over the years, I've come to believe (through observation with several youth programs) that bat speed helps generate the greatest gains for hitting with authority. I'm not saying that proper mechanics also play a part, because they certainly do! But at the younger ages, the minus 12 bats really help the kids generate some incredible bat speed.
>
> > -Deano
>
> >That is an interesting observation. So, with my twelve year old daughter, assuming that she uses the proper swing mechanics, would she create more power and thereby hit the ball further with a -12(31/19)bat or a -10 (30/20)bat. She seems to create more bat speed with the -12 bat.
>
> Phil C.

Phil,

I often look at bat speed just like the martial arts guys that like to drive their forearms through several concrete blocks on one swing. Swing that forearm faster and harder with more downforce and you'll definitely break more blocks! Generating more bat speed "should" (and I qualify "should") allow the hitter to hit the ball harder, assuming all other factors remaining unchanged. But that's just it.....there are other important factors like proper rotational mechanics that "magnify" the bat speed effect.

The only time when a light bat can become an impedence to good performance is with a really slow pitcher. In those cases, I just have the kids move to the front of the box and tell them before each pitch to stay back and be patient.

If your daughter is average size, I would favor the lighter bat. If she is a big girl, then the slightly heavier bat will most likely feel more comfortable to her. Good luck!