Posted by: Mike Myers (mike.myers@bell.ca) on Tue Jun 7 08:55:04 2005

Hi Jack,

Excellent work with the site.

I have been reviewing an argument re: the correct swing plane at contact for baseball vs softball.

There is an interesting presentation at the following site (of which I’m not affiliated):

http://www.swingmechanics.com/What_Will_It_Do.htm

Shown is a softball bat hitting a softball. Swing angle, and whether the ball is hit above or below center line influences post-contact ball spin and trajectory.

Although not shown, backspin introduces loft as per Bernoulli effect (i.e. lower air pressure on top of ball creates lift).

The ratio of bat-to-ball cross-sectional diameter appears to influence how much backspin is likely to be induced by a downward hit on the lower half of the ball. This may be significant in softball.

This ratio in baseball is much closer, and I believe it would be more difficult to introduce significant backspin (compared to translational speed) by swinging down on the lower half of a baseball.

As such, for baseball, it is best to hit the ball square with slight upslope.

Can you comment on the validity of this argument?

Regards,
Mike.