The Seattle post-intelligencer. [volume] (Seattle, Wash. Terr. [Wash.]) 1888-1914, 1896-07-19
MYSTERY OF A .SEBALL CURVE.
How the sphere 1. Made TO Twist and
irf<s. or Drcp-


Rise or Drop
Tt. vzlrs az p5.chsr zep<-fs uFcr sew.
e-aI things but r1atray On MS znzisfy 20
ruaEs TIE bah curve Il has p1zzaes1
rAzy 20 ses how a1d why Il - possible 20
tH-ex : ball so that II viii start for
xaS@z puEnt s75 miu then. Wills n the
ar. charge stz direction. 10 tie coz<ussc1
Of the batter who = trying 10 hi T. Ia-
Ike the mystery o. RE Boomerang. which
has not been solved ~ 70 date. the uys-
tery % baseball Curve can be explained.
and here Is the expxgzatkcr. II the 1-sV
place. the curve IS produced entirely ~
tire rotation o. tHsst given TO the ball IS
i leaves the zngers CT the hand that
throws il a simple rule gives = key 20
every possible curve-;ne bail Vii curve
81 the direction il which the front % Il -
twisting This can be more easily il2s-
fraEel by as@azs OF q tennis racket and
bail. In the ordinary overland cnE serve
the ball Is given giaEc1ng stroke. that
makes tire front Of y twist so rapidly from.
right 70 lsfr that By the time the ball IS
over tAe net i has slowed well over 20 the
Run q Lead pencil fAro1gh a bail Of yarn
and hold the pencil il front OF yoa and
straight UD and down. Twist the ball 50
that the front OF 1.-THE side away from
yo2-ss moving from right 70 lekts and then
suppose & u be moving rapidly away from
vol The right side OF the ball will then
De turning in the direction II which the
oau Is moving. ard. consequently. the
sphere viii not Only meet the straight re-
sistance OF the air caused hy the speed
with which il IS shrown. bar Will meet with
the additional resistance caused by the
right side Of ;he ball twisting against the
air as i turns in lis fight. The result is
that the ball simply slides OF the air. in
the direction that the front % X IS twist
ing as il goes its way. In this case the
swinging OF the right side against the air
pushes the ball % the left: the turning OF
the LETT Of the ball away from the air re-
sistanse caused by the throw reduces the
air pressure o. that side 20 practically
nothing. making II easy for the piisd-up
air cushion Of the right side TO slew the
ball 70 the left side, that has practically
no air resistance 70 meet.
To illustrate with other tennis strokes:
An upward cut stroke OF the racquet makes
the ball go up for a given distance on
line and then drop like shot; this stroke
turns the ball 80 that the back of II goes
Up. iEs top forward and the front down
toward the ground. In exactly the same
way the extra air wave created BY the for
ward motion OF the top Of the bah makes
IL drop suddenly.
Another Illustration may be easily found
IN the ease Of a boat that is driven through
the water; the resistance OF the water
forms what Is called a bow wave on each
side OF the bow. SPIT your beat IN two
from end 70 end. take the right-hand piece.
board up the fiat side made by the split
ting and then push the half boat through
the water again A bow wave viii be
formed On the right-nand side that VIII
make what remains OF the boat slide over
10 the left: the absence OF resistance on
that side makes this inevitable. So with
a baseball; the atmospheric how wave
caused by the twisting movement of one
side OF the ball against the air siews the
bail over in the direction in which there
Is least resistance.
X viii thus be seen that the ball may be
made 10 curve in any direction that the
pitcher can make the front OF Il twist
Not only UP. down. out Ito the pitchers
lefD and In Ito the pitchers right. but in
any intermediate direction. Set up big
compass dial facing the pitcher. with the
north at the top, the east at his right and
the center about on level with his shout
der. A perfect curve artist should be able
70 start the ball for the center. and then
have IL curve In the direction Of any point
on the compass dial.
A peculiar side of the question is that
hardly a ball is thrown that does not curve
in one direction or another Watch ball
thrown across the diamond from short
stop or third base 10 first base. man in
either OF these positions who throws with
long arm will almost invariably give the
ball twist b. the swing OF his body. that
makes the front OF the ball turn 70 the
thrower's right and curve in the same d.
rection When this curve Is allowed for
the bah goes TO first all right. but il often
Isn't calculated on and a Wild throw Is
charged against the man who started IL
In the right direction. but with "a BIT OF
a twist" on Il. Thousands OF overthrows
have resulted from the rise given the bail
through the twist caused BY the snap
down OF the hand and wrist az the end OF
a straight overland throw. As the hand
Ia brought down al the finish of a straight
throw the bali slides of the fingers in a
way that makes the back OF the ball twist
down, the unders.de OF Ii twist forward
and the front up. The air resistance or
wave formed BIZ the underside of the bali
turning against the air lifts ne ball until
less OF speed and gravity overcome the
upward movement caused by this twist
ing. Some catehers throw TO second base
in this way. the bah seems 10 go on
straight line for part of the way. then 10
lift a little from the effects Of the twist.
and finally 10 almost drop into the second
bsseman's hands.
This upward curve or rise" OF the ball
Is often shown in the wax that the ball
goes on a perfect level for some distance:
the upward tendency IS just enough 20 bal
anse the natural fail of the bali toward the
ground. Some pitchers have developed
the trick wonderfully. Carter. OF Yale, is
said 10 have thrown rise" balls that hit
the catcher's baekstop ninety feet back
OF the home plate az points higher than
those ~ which the balls crossed the plate.
vrheel-nea should be careful 80 keea
kerosene or kindred oils from the nickel