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Most baseball players don't realize
it, but they are constantly being influenced by
science and technology. Here are some
explanations of how science and technology have
shaped the game of baseball.
How
does a Runner Attempt to Steal Second?
A runner on first base trying to
steal second must get to second base during the
time that it takes the pitcher to deliver the
pitch and the catcher to catch the ball and throw
it back to the second baseman or shortstop, who
will attempt to tag out the runner.
Of course, the runner has taken a
lead off first base. That means that the distance
to be run has been cut down, which will shorten
the runner's time in running from first to second
base. And the runner will probably slide into
second base.
What's the purpose of a Slide?
Does sliding help a runner to
get to second base any faster? Of course not. It
does help him or her come in under the throw, but
the opposing infielder is expecting that and will
try to tag the runner low down. Actually, the
runner is using the slide to slow down. Running
flat out might cause him or her to run across
second base and the runner must stop there or he
or she can be tagged out for not being on the
base. The runner is really using the friction
between the body and the ground to decrease
acceleration and stop in a hurry.
Why does a Runner Round the Bases?
Inertia has been defined as
the characteristic of all bodies that causes them
either to stay at rest or to stay in constant
motion - that is, unless an outside force acts
upon the bodies. We have all experienced this when
an automobile goes around a turn. Remember that
objects tend to go in a straight line. If a turn
is taken too fast without seat belts being
fastened, we tend to slide right across the seat.
Now suppose a batter is trying to
score an inside-the-park home run. The batter
must run as fast as possible, so he or she does
not run straight to first base, turn left, run
straight to second base, turn left, etc. What
must be done is called rounding the bases.
If the player were to make a sharp
turn at each base, it would be necessary to stop,
then turn, and then head to the next base. There
is no time for that, so the runner must follow a
curved path around the infield, fighting inertia
while keeping most of his or her speed. Running
in a curved path is easier than stopping at each
base and making a 90-degree turn toward the next
base.
Think of how a runner tries to beat
out an infield hit. He or she runs straight
toward first base, trying to beat the throw. This
is covering the shortest distance between home and
first. But if the player thinks there is a chance
to stretch the hit into a double, he or she will
follow a curved path toward first, therefore being
in a position to make the turn toward second more
effectively.
How Does a Player Catch a Hard-Hit
Line Drive?
Newton's second law of motion says
that the net force on a mass is directly
proportional to, and in the same direction as, the
acceleration of that mass. In other words, force
= mass times acceleration, or F = ma. The mass
stays the same, of course, so if the force
increases or decreases so will the acceleration.
And if the acceleration increases or decreases, so
will the force.
When an infielder catches a
hard-hit line drive, he or she does it
automatically. The ball is still traveling along
an almost straight line, and it may even still be
accelerating. What does the player do? Stand
like a statue, holding the glove where he or she
knows the ball will hit it? No. That would hurt.
Instead, just as the ball hits the
glove, the player moves his or her arm and hand
back with the ball in the glove. And if the ball
is a real screamer, the player's whole body may
move backward. This is not because he or she is
knocked back by the force of the ball. What is
happening is that the arm, hand, and body "give" a
little bit, and this spreads the force of the ball
hitting the glove over a greater span of time.
The point is that when a ball is caught, its speed
must be reduced to zero almost immediately. By
having the hand give on impact, the player is
increasing, by a fraction of a second, the time of
reducing the speed to zero. The result is that
the hand feels less shock and does not sting as
much.
How Does a Player Throw a Ball to
Make it go Farther?
Everyone knows that the
acceleration due to gravity is with us all the
time. Drop a glass, and it will fall to the
floor. Gravity acts on any thrown object, too.
You know that your throw is eventually going to
hit the ground, so if you want the ball to go
farther, you have to keep it in the air longer,
before gravity forces it to earth.
To do this, a player must increase
the angle of the throw when he or she wants it to
carry a longer distance. Throwing to the plate
from center field requires an arched throw, which
will keep the ball in the air. If it is thrown
flat, even with the same amount of force, it will
hit the ground sooner.
But that doesn't mean that the
pitcher, when throwing a fastball the short
distance to the catcher's mitt, can throw a flat
ball. He or she, too, must put some arch in it,
although not as much as the center fielder.
As soon as the ball leaves the
pitcher's hand, gravity begins pulling it
downward. Even the fastest pitcher's smokeball
may drop as much as 2 ½ feet by the time it
reaches the catcher. That's why there is such a
thing as a pitcher's mound. Even so, the pitcher
must always aim a little higher than the point
where he or she wants the ball to go. The pitcher
knows that the ball will reach a point where its
upward acceleration will be zero and the ball will
start to drop.
Can Pitching be Learned?
Two researchers - Dr. Joe P.
Bramhall, a team physician at Texas A&M
University, and Dr. Charles Dillman, of the
American Sports Medicine Institute - videotaped
the deliveries of 48 major league pitchers,
including Dwight Gooden, Nolan Ryan, Roger
Clemens, and Dave Stewart. They found out that,
although these men have different styles, from a
scientific point of view they still pitch in the
same way.
As far as the arm angle, elbow angle, shoulder
angles, and balance were concerned, these men do
the same things.
The purpose of the study was to
teach young players the correct way to pitch and
thus prevent them from making mistakes that might
lead to injuries of the pitching arm. The
researchers came up with some rules:
1. In the windup, the
pitcher should be balanced at the top of the leg
kick, coiled, and ready to spring forward.
2. The length of the stride
should be slightly less than the body height. The
left foot of the right-hander (or the right foot
of that left-hander) should step directly toward
home plate, moving to the side six inches or less.
3. In the delivery, the
back rotation of the shoulder should not be
greater than 165 to 180 degrees. The elbow should
be flexed between 70 and 115 degrees.
4. In the follow-through, a
smooth, extended motion should slow down the
pitching arm gradually. The throwing shoulder
should be aligned over the opposite knee after the
release of the ball. The upper body should be
slightly flexed.
How is the Curveball Thrown?
The most common effect
of spin in sports is something that some people do
not believe exists - the curveball in baseball.
You can still find some people who think that the
curveball is just an optical illusion.
The argument of
whether a baseball can curve went on for so many
years that scientists finally got into the act. A
long strip of lightweight tape was attached to a
baseball. Then a major league pitcher was asked
to throw a curveball. This is usually done by
gripping the ball with the thumb and first two
fingers only, with the inside of the thumb pressed
against one of the seams of the ball. The ball is
then released with a sharp outward snap of the
wrist. And the friction between the ball and the
thumb and fingers starts it spinning as it heads
toward the plate.
After the pitcher threw
the ball, the scientists counted the number of
twists in the tape. This gave them the number of
complete spins the ball had made. Then the ball
was placed in a wind tunnel and spun at the same
rate. The results indicated that it is possible
to make a ball curve as much as 18 inches away
from a straight line within a distance of 60 feet,
six inches - the official distance from the
pitcher's mound to the plate. But the ball must
be traveling about 100 feet per second and
spinning at a rate of 1,800 revolutions per
minute.
Here is what happens:
Any thrown object meets air resistance, almost as
if there were a wall of air rushing to resist it.
But the spinning ball changes this solid wall of
air. Suppose that it is thrown by a right-handed,
sidearm pitcher. The spinning ball pulls air
around it, but the pressure is increased on the
right side (toward third base) and decreased on
the left (toward first base). It is spinning
counterclockwise, in the same direction that a
base runner runs around the bases.
The increased pressure
on the right side runs into the wall of air that
has piled up in front of the ball and causes the
ball to veer to the left. The ball is following
the path of least resistance, as the air pressure
is lower on the left side. By the way, a
curveball thrown by a sidearm left-hander would
curve in the opposite direction, since the ball is
spinning clockwise.
How is the Knuckleball Thrown?
The
knuckleball, too, depends on air resistance. It
is a tricky pitch, and most catchers hate to be
part of the battery with a knuckleball pitcher.
You never know where it is going - toward the
dugout, toward the batter - moving erratically up,
down, or sideways as much as 11 inches. The
reasons for this are the seams on the baseball and
the pitch's slow rotation of as little as a
half-spin between the mound and the plate. That's
against the typical fastball's eight-time
rotation.
The ball is held with
the index and middle fingers (and the nails)
digging into the ball just behind the seam's loop,
with the other two fingers on the side of the ball
and the thumb along the side of the underseam.
The drag is greater on the smooth, unstitched part
of the ball, and the ball gets a deflecting push
from the smooth side toward the stitched side. As
the stitches rotate, the force changes direction.
The less spin, the more deflection.
How Does a Bat Work?
One of the common
simple machines used in baseball is really a lever
- it's the bat. A lever is only a stiff bar
arranged to turn around some fixed point. The bar
does not even have to be straight. The fixed
point is called the "fulcrum." The function of
the lever is to change the position of a load by
applying a force. In the case of the baseball
bat, the fulcrum is at the small end, the force is
at the point where you grip the bat, and the load
is where the ball strikes the bat.
A lot of people argue
about what is the best bat. There are those who
stick with the old-fashioned wooden bat (including
the professional leagues) and those who opt for
the aluminum type. And others think the only
difference is the sound the bat makes when it hits
the ball.
But mechanical
engineering students at Tufts University in
Medford, MA, decided to do some investigating in
1991. They used a bat that weighed 32 ounces, had
a diameter of 2 ¾ inches (a quarter-inch thicker
than standard wood and aluminum bats), and was
made of materials that included wood, glass-fiber
composites, resins, and fabrics. It supposedly
responded like a hardwood bat and had the
durability of an aluminum bat.
Developed by Steven Baum of Traverse City,
Michigan, it was tested on the Tufts campus by the
baseball team (only in practice), and the Boston
Red Sox and Detroit Tigers used it in spring
training. The idea was to market the bat first to
minor league teams, since wood bats have such a
long tradition in the major leagues.
One of the Tufts
players claimed that the experimental bat had a
bigger "sweet spot" than the usual bat. But he
pointed out that it stung more than an aluminum
bat if he didn't hit the ball on that sweet spot.
What Makes a Player a Good Home Run
Hitter?
Everyone loves a home
run hitter, and some years ago a study was made on
several home run hitters. You might guess that
they had more going for them than mere strength.
James L. Breen, the head of the Department of
Physical Education at Tulane University in New
Orleans, found that there were mechanical traits
that great home run hitters had in common. He
came up with his list by studying hundreds of
major league batters and thousands of feet of
film. Finally, he concentrated on six of the
leading home run hitters of the 1950's and 1960's:
Stan Musial (Cardinals), Ernie Banks (Cubs), Hank
Aaron (Braves), Willie Mays (Giants), Ted Williams
(Red Sox), and Mickey Mantle (Yankees).
Breen's list of
mechanical traits was made up of four items:
1. The center of gravity of
the player followed a level plane throughout the
swing. (The center of gravity of a body is that
point in the object at which the mass is evenly
distributed in all directions.)
2. From his stance, the
batter was able to adjust his head from pitch to
pitch.
3. The length of stride was
the same on all pitches.
4. After contact with the
ball, the upper body position was in the same
general direction as the flight of the ball.
Breen also found that
if the body is kept level at the center of
gravity, the bat will be swung in a level path.
This is the most effective kind of swing. Having
the proper head position lets the batter watch the
pitch for the longest amount of time. This is
especially important when the pitch is a breaking
ball, such as a curve or a sinking fastball. The
longer the batter follows the pitch with his eyes,
the better he will be able to see the point at
which the pitch breaks. Also, by holding his head
properly, the batter can reduce the angle at which
he sees the ball - which means he will see it more
clearly.
If the batter keeps his
arms straight when he is swinging, he can bring
the bat around much faster than if his arms are
bent. Hitters who bend their arms tend to pull
the handle of the bat around as they swing. That
messes up the lever action of the bat.
Quicker bat speed, along with the
ability to watch the ball for the longest period
of time, helps the batter to judge more accurately
where the ball will be when it is hit. The
average batter, looking at a pitch that is
traveling 80 miles per hour, has to start his
swing when the ball is about 33 feet from the
plate. The home run hitters in this study were
able to wait until the ball was only 24 feet from
the plate.
The speed of the swing
from the time the bat was swung until contact was
made varied in this group of hitters. Musial's
time was 0.19 seconds, and Williams' time was 0.23
seconds. An average hitter's speed would be about
0.28 seconds.
Each of these hitters,
although their batting stances were different,
took the same straightforward stride as he swung.
And each had a similar follow-through motion. As
the bat was swung, they pushed off on the back
foot, putting all of their force in one
direction. Their weight was taken off the back
foot when contact was made with the ball, which
shifted the center of gravity of their bodies in
the direction of the ball. Poorer hitters often
shift their centers of gravity backward by putting
their weight on the back foot. This results in a
loss of power. Gravity, stride, straight arms,
head position - whatever these men were doing,
they obviously were doing it right.
More on the Science of Hitting
You
can forget your thinking caps. Baseball, with its
many strategies, is often thought of as being a
thinking person's game. But it may be that the
smartest hitters leave their brains in the dugout.
Yogi Berra's statement that he couldn't think
while he hit might have been one of the smartest
things that that baseball analyst ever said.
Tom Hanson, a baseball coach
at Skidmore College in Saratoga Springs, New York,
wrote his doctoral dissertation on the thinking
hitter. He claimed that batters simply have no
time to think during the four-tenths of a second
it takes a good fastball to go from the pitcher's
hand to the catcher's mitt. Hanson contended:
"If you are thinking, you are in trouble.
Information should go from your eyes to your hands
and bypass the brain." The best hitters, he
found, are the most relaxed hitters. "The key is
not to get tense and anxious. That tightens the
muscles and a tight muscle is a slow muscle."
And Judson Berkey, a senior at
Thomas Jefferson High School for Science and
Technology, designed a computer model in 1991 to
simulate the flight of a baseball. He had come
across a study by scientists at Tulane University
that assumed that the spin of the ball does not
decrease as it travels through the air. That
didn't make sense to Berkey, who pointed out that
"the ball doesn't come down whizzing through the
air. It's coming down pretty soft."
From his computer work, he
theorized that to launch a ball the farthest, a
batter should connect with the ball at an angle
between 32 and 40 degrees from the horizontal and
apply as much backspin as possible.
As he said, and you might have to
go to a physics teacher to get this translated:
"Previous research stated that the vertical launch
angle of the baseball from the baseball bat that
maximizes the distance the ball travels decreases
considerably as the magnitude of the spin
increases. These results, however, neglected two
aspects of a baseball in flight. They neglected
to consider the variation of the coefficient of
drag with the velocity of the baseball and the
spin reduction due to the torque that is produced
by the spin of the baseball."
Finally, Dr. Paul Legace of the
Massachusetts Institute of Technology noticed
something after the roof behind home plate in
Boston's Fenway Park was torn down following the
1988 season and replaced with a higher one. Balls
that once soared into the stands were falling
short.
He had students in his aeronautics
and astronautics courses build a wooden model of
the ballpark. The model was then put in a wind
tunnel for tests. He found that the higher stands
created a vortex, or backwind, that could cause a
fly ball hit to center field to travel about ten
feet less. |
