Posted by: Joe Hernandez (coach2hit@yahoo.com) on Tue Jun 20 20:01:30 2006

> Joe
>
> Is not batspeed a function of strength (strength used to advantage with proper mechanics)? More precisely, 2 bats of equal mass striking a ball on the same spot and traveling (on ball contact) the same speed should result in equal "pop" regardless of the hitter's strength (all else being equal...that is pitch type, barometric conditions etc.)
>
> Where strength DOES come into play is with bat mass. A stronger hitter should be able to get a heavier bat (a bat with more mass) up to speed at contact, resulting in more "pop", than a weaker hitter who must use a lighter bat to get the same batspeed at contact. Or conversely, a 40 oz bat traveling at a slower speed at contact than a 20 oz bat may result in the ball traveling a farther distance (all else equal).
>
> So while Barry Bonds IS stronger than I am, he'd have nothing on me (in terms of "pop") if I developed the mechanics to attain his batspeed (again, all else equal).

Nativetrout,


I am not sure I understand your question. It seems like the formula of "strength x speed = power" is exactly what you need to see. Barry Bonds bat speed of approximately 68mph coupled with his strength is what enables him to drive the ball despite using a 33 ounce bat. But it is far more involved than that...there are many other factors that are in play that enables Bond to add distance to a hit ball. It's just that in a forum like this, great as it is, it's difficult to get across every single nuance. We are all contributing by answering someone's question, only to have someone else misread it or read it out of context before a barrage of unrelated questions are posted.

But you have some legitimate questions so let me see if I can answer some of them to your satisfaction. If I can, great...if not, sorry. But let's try...

When a pitched ball collides with a swinging bat it is a violent collision. It is important to understand what is velocity, which is a vector quantity that includes the speed and the direction of the ball and bat. There are many aspects of velocity such as “the velocity of the bat", "the velocity of the ball", "the location of the hit of the ball and the bat", "the angle of the hit", "weather conditions", "the coefficient of restitution between the bat and the ball", "the condition of the ball", "the direction of the bat at impact", "the direction of the ball on impact", as well as the "spin on the ball". Add to this dozens of other factors and variables and you begin to appreciate and understand how involved the physics of hitting a ball is. It would be nice to have some simple explanation that can be easily measured and implemented to make all of us great hitters. Unfortunately this is not the case.

Not to mention that it is important to understand the sequential aspects to hitting a ball. The legs still "deliver" the hips. The importance of proper sequential kinetic energy transfer must be understood. The hips can only deliver the torso, which in turn delivers the shoulder, if the hips begin its rotation upon the "peak" of kinetic energy transfer from the legs.

Thinking that one segment of the body plays a greater role than another is exactly what too many coaches and hitters misunderstand. Each transfer of kinetic energy must move sequentially and at its "peak" before the next body segment acts upon it. Anything sooner and you do not "maximize" the kinetic energy transfer, and anything "slower" and you waste kinetic energy. Either scenario will not only take away from the velocity of a swing, but can add to the breakdown of good hitting mechanics.

The legs move slower because it is a greater anatomical body mass, however it still creates a larger force (mass x acceleration). At it's peak is when the hips need to come into play...this transfer of kinetic energy continues to the smaller anatomical parts (from the legs, to the hips, to the torso, to the shoulders, to the arm, to finally the wrist and fingers). As the kinetic energy is transferred from the larger body mass to the smaller, the transferred momentum magnitude is accommodated (assuming, and hence the need for good hitting mechanics) by the smaller body mass thereby increasing velocity. The smaller body part needs to increase its velocity in order to be able to "efficiently and effectively" receive the transfer of kinetic energy from the larger body mass. It is even more involved as Jack Mankin as so well explained throughout this website.

That is why the emphasis on just one aspect of the body as a "source" of velocity makes no sense.

Another area that needs to be understood is what I mentioned before, the “coefficient of restitution". This is the physics term for what happens to the ball and bat before and after contact is made. Understanding the coefficient of restitution will enable you to understand how a ball can come off the bat faster than it came into the bat because you are putting more energy in from the bat itself. In other words, you have added something and that something is the speed of the swing. Both the bat and the ball affects the coefficient of restitution.

Let us not forget the importance of hitting with the "sweet spot". The sweet spot is just that, a spot...it is not an area....it is a single point on a bat. Hitting on the spot will enable a hitter to transfer the most energy into the ball....anywhere else and you lose energy because the bat absorb too much energy. To complicate matters even more, the sweet spot, also known as the percussion of the bat, changes anytime you hold the same bat in a different location...that means that if you choke up an inch the sweet spot changes. Of course it would not be too far apart but different nevertheless. Good hitters manage to hit with the sweet spot more often than not...mediocre hitters miss more often. What this means is that a hitter needs to decide how he is going to hold the bat before he can decide where the sweet spot is!

Of course we are talking wood bats...aluminum bat are more forgiving.

Also another thing to take into consideration is the size of the bat. But overall, it is more important to generate bat speed than it is to get bat mass. A ball will travel farther when a heavier bat is used if a hitter was able to use a heavy bat plus swing with the same velocity of a light bat while hitting in the center of percussion. The problem for most mortals is that they cannot swing a heavier bat as fast. I don't know anyone that can swing a 42 ounce bat as fast as a 33 ounce bat, including Barry Bonds.

There is so much more. But I hope this answered some of your questions.

My Best,

Joe Hernandez