From a book, Keep Your Eye on The Ball by Bahall and Watts
They use a formula from a program called Bat Chooser
I recommend reading the entire chapter however hopefully you get the point.
For fast pitch soft ball only
Note: Recommended bat weight is in ounces, age in years, height in inches and weight in pounds
height/ 7 + 15
example 5' 5" 5 x 12 = 60 + 5 = 65 inches divide by 7 = 9.28 + 15 = 24.28 oz.
The concept for me when teaching hitting is to put the sweet part of the bat on the ball as consistently as possible to generate maximum force.
This goes to f = M A force = mass (bat weight) x (acceleration bat speed)
If you have a good hand path established you should be able to hit the sweet spot more often.
From the book, The Physics of Baseball by Robert K. Adair, PhD
"Such modeling is simplified by the realization that a player swings a bat very much as he would a weight on the end of a rope; to a very good approximation, the forces on the bat exerted through the hands are directed along the axis of the bat. Hence, if the motion of the hands is known throughout the swing, motion of the bat can be determined."
"To this we add the (very plausible) condition that no player can swing a heavy bat faster than he could a light bat. And we hold that no player can put more energy into a light bat than into a heavy bat."
"If we assume that the arc of the hands-and bat- is the same for a light or heavy bat, the larger force that it is possible to apply to the more slowly moving heavy bat will result in a larger energy transfer to the bat."
So we focus on using a good hand path and matching the plane of the pitch and staying in the Big Zone by giving the hitter the concept of keeping the hands inside the path of the ball.
When working with a student for the first time I set up a Schutt travel tee exactly 11 inches off the plate at the outside back corner of home plate and they measure off from home plate and I chalk a straight line (line of force) that they stride forward. We want to make sure they did not step away or towards the plate. Most can not even come close however after the lesson we repeat and they can do it and they are surprised.
Chip Mike said he saw you in Florida at the NFCA and you saw the WhipHit and we have been using this for three years now along with the hammer bat. This is how we focus on putting the sweet part of the bat on the ball as it is only 2.5 inches in diameter. I do not know of any other drills or devices that gives the hitter instant feedback while doing the drills.
Once the hand path is established we measure bat speed and the hitter chooses what bat works well for them as to end loaded, knob loaded or balanced.
Hope this helps...
