Posted by: Mike Myers (mike.myers@bell.ca) on Sat May 21 20:04:10 2005

> > > > >>> The studies sited are flawed. I have far more faith in
> > > > Newton's third law, for every action there is an equal and opposite reaction. Therefore collision of ball on he bat tends to create deceleration of the bathead. Sustaining lag is your best defense against deceleration. <<<
> > > >
> > > > Hi Mjb
> > > >
> > > > The data from these bat company tests (3 that I know of) show that deceleration of the bat-head during bat/ball collision (about 1/2000 second) is proportional to the bat’s mass. That is consistent with Newton's third law. What evidence do you have to support your statement that these studies are flawed?
> > > >
> > > > Please explain what you mean by, “Sustaining lag is your best defense against deceleration.” It appears you are saying that having a static bat at the lag position will allow the batter to generate greater contact speed than having the bat accelerating through the lag position.
> > > >
> > > > Jack Mankin
> > > ******************************************************************
> > > The studies do not include the arms in the equation. The arms andbat make up the lever system that hits the ball. The arms add mass.
> >
> > Please read studies of batted ball rebound velocity on free vs clamped bats:
> >
> > http://www.kettering.edu/~drussell/bats-new/grip.html
> >
> > Measurements show that the collision between bat and ball is over before the bat handle has even begin to vibrate and the ball has left the bat before it even knows the handle exists. Experimental evidence comparing the effect of different grip conditions on resulting batted-ball speed conclusively shows that the manner in which the handle is gripped has no affect on the performance of the bat.
> >
> > Mike
> ***************************************************************
> Study #1 says it makes a difference. Common sense as well.
> The energy of the ball is going decelerate the bat unless there is mass and force to prevent it as in a bat hanging from fishing line.

Study 1 was flawed - the bat was allowed to freely translate back creating an realistic boundary condition. See studies 2-5, and conclusion.

Ball contacts bat for 1/2000s. There is insufficient time for distant mass (i.e. arms) to affect batted ball speed. Consider the aluminum bat trampoline effect - the metal bends, and returns to normal before external mass is a factor.

Similarly, it's concluded forcing the bat at contact has no affect on batted ball speed. Only final batspeed is important.

Mike.