Axis tilt: Angle between axis of rotation and the
horizontal plane - caused by the bowler at the
release, represents an angle of the axis rotation
above a horizontal line through the middle of the
ball. Axis tilt
represents the vertical alignment of the hand at
release.
Tilt is changed by the position of
the wrist. By positioning the wrist left or right
during the swing of the ball,
the position of the thumb and
fingers change the angle
of the fingers during the release. Ball spin
is the result of axis tilt. The higher the
axis tilts, the more the ball spins, and the
resultant path of the ball is extended.
As the ball is released, the fingers
cause the ball to rotate around to the ball's
vertical axis. This is seen as ball spin.
Most bowlers, during their release, have some tilt.
The degree of tilt can be viewed and measured as the
circumference of the ball track.
Axis tilt is the distance from one side of the track
to the other on the negative side of the ball.
This distance is converted into degrees using an
axis tilt chart.
The more axis tilt, the less the resultant hook.
Should axis tilt become equal to axis rotation, the
ball will not hook. In order for the ball to
hook, axis rotation must always be greater than axis
tilt. The axis of rotation defines how
far the axis rotates from a pure forward roll
in the horizontal direction. The axis tilt
defines how far the top of the ball is above the
middle of the ball, and is measured in degrees.
Axis tilt
promotes skid. The more axis tilt a ball has,
the later the ball transitions into a roll.
The less axis tilt a ball has, the sooner the ball
transitions into a roll.