Posted by: Steve (stevo@linedrivesports.com) on Thu Jun 21 23:09:14 2001

> > Since gravity is a consistant force ALL thrown balls start to drop
from the path at release the instant it leaves the pitcher's hand. And
the speed has nothing to do with it. This is a fundemental
unchangeable law of nature and no spin, trajectory or wishfull
thinking can change it. THERE IS NO RISE BALL.
>
> Be careful in your use of physics.
> There are two reasons for a ball to 'rise'.
> One is backspin. While backspin creates upward forces on a ball,
those upward forces do not necessarily cause the ball to change its
path upward of its normal course of flight. The amount of spin on a
softball vs. its mass is critical here. Gravity starts pulling the
ball down upon release. I suspect that a softball is too heavy to have
backspin literally counter the effect of gravity AND additionally make
the ball curve up.
> You can throw (or at least hit) a ball that rises with a whiffle
ball - it has much less mass and better surface for the spin to
interact with the air it moves through.
>
> However the force of gravity acts only on the vertical vector of a
thrown or hit ball. To wit, a rifle is aimed to fire at true
horizontal. At the moment the bullet exits the barrel, a second bullet
is dropped from barrel height. Both hit the ground at the same time.
All the force applied to the fired bullet is horizontal. Gravity acts
on both bullets as if they are 'standing still' - no vertical momentum
except gravity.
> If instead you fire the gun at a 45 degree upward angle, half the
momentum is forward, half is upward. Gravity must first counter the
upward momentum of the bullet until it stops climbing. At that point
the bullet starts to come down. It accelerates due to gravity until it
hits the ground - or its velocity levels off when air resistance
counters further acceleration.
> The bullet fired up lands much later than a bullet dropped at firing
time.
>
> The same holds true for a softball pitch. If the pitch has an upward
trajectory, it does not start dropping from release point. It starts
losing its upward momentum as the pull of gravity counters its ascent.
> So yes, the ball starts to drop from its original upward path
increment by increment due to gravity. But it may still be climbing,
albeit more slowly by more slowly, until it levels off.
> A hard thrown softball - 65-70 MPH - can climb for the 35+ feet of a
fps pitch. Its not spin, its trajectory
> An upward trajectory does rise.
>
> Backspin diminishes but does not entirely counteract the force of
gravity. Backspin balls drop less due to spin.
> Pitches thrown upward rise until gravity stops their rise.
> That's physics reality.
> Lay off the high pitches.
> That's fps reality.
That was the best explanation in this thread Major Dan. Any of you who
have ever seen an upper level mens fastpitch pitcher will have no
doubt in their minds that a ball can rise due to trajectory, speed,
and backspin. There are/were also many pitchers who could throw the
low rise that looked like it was coming in below your knee and in the
last 5-8 feet before the plate it jumped into the strike zone. I have
seen girls that could throw this type of pitch albeit less
consistently but in all cases they had to alreadt posess the speed
along with the backspin mechanics to achieve it. A little breeze
blowi