Posted by: Shawn (mariner0324@yahoo.com) on Fri Oct 21 13:49:55 2005

> Are you saying Lau and Schmidt are incorrect, well might as well include Epstein as well, in that there isn't a weight shift or linear move? <<<
>
> Hi Shawn
>
> I am saying that that a linear movement of mass (the hitter’s axis moving forward) is not necessary to generate power for the swing. I further state that just because a batter shifts the responsibility for supporting the body’s mass to the front leg does not mean there was a forward transfer of momentum.
>
> Yes, some good rotational hitters do (and some do not) have a linear movement of mass during the stride. However, before the swing and body rotation is initiated, any forward movement slows to a stop and the body rotates around a stationary axis. Therefore, during the swing, there is no linear movement of the body’s mass or linear momentum available to be transferred.
>
> It is the transfer of rotational momentum that generates bat speed. I would hope that Lau, Schmidt and Epstein agree. If not, I am always here to discuss it with them.
>
> Jack Mankin

Jack,

I have you disargee with you. If weight shift wasn't important then the many amateurs doing it wrong would have good power.

A linear weight shift is important for power, how much the mass moves forward is different for each hitter. There is two improper ways of rotating, one is with the weight staying over the back foot and the other is when the hitter pushes back off the front leg, sending the body backwards. These are two common errors with amateurs. The fact is they never get the 'mass' into the swing. The body weight isn't used to hit the ball.

This weight shift doesn't have to be great, or positive move. Although it is present in the best hitters. One of the problems with trying to be more rotational is a lack of weight shift. Just like someone with to much might have a lack of rotation. The answer isn't to forget about weight shift while learning to rotate. Without weight shift the swing is rather weak and lacks power. This is somewhat like creating leverage in the swing during the loading and unloading, first off the backside and then against the frontside.

It doesn't matter what you call it. It is important in a power swing.

We are not saying there is a weight shift during the swing. The swing is very rotational. The preparation for the swing is the linear part.

There is no one who comes to a stop as you say it and then rotates. Linear movement is not transfered in that manner. There is no stopping in a good hitters swing, that is a problem area in a amateurs swing. Loading and unloading (which is where weight shift happens) is dynamic and fluid, it has rythym. There is a small change of direction between the loading and unloading. It isn't not a stop of actions, the actions blend together.

If force stops it equals zero, there is no stopping of the force production in a good swing. This might come to as a surprise to most but the stride is part of the force production. This is when weight shift happens durng the loading and unloading phase. You do not start and stop this force production unless you are adjusting to an offspeed pitch.

I disagree with your theory that hitters come to a complete stop before rotation. I also disagree that weight shift doesn't matter in a good hitter. If this was true there would be alot more better hitters who just rotate.