Horizontally Thrown Knife viewed from the side

A. STRAIGHT THROW (SHORT DISTANCES)
B. SPINNING THROW
1
1
MORE AIR
RESISTANCE
AT GREATER
RANGES
Estimating Distances
A knife thrower must be able to judge distances with a
good degree of precision in order to throw accurately. Such
ability can only be gained from long hours of practice. Begin
with established distances which are marked off. (See the
following section on training.) Once a Ninja learns to hit a
target from any distance from five to thirty feet, he or she
should practice to be able to hit the target at any range in
between. Long distance throws from thirty up to fifty feet
can be practiced in advanced training.
Knife Rotations
Short range throws, approximately ten feet or less, usually
cause a knife to travel in a straight line to the target. Beyond
this range, however, throwing knives execute one or more
spins or half spins (up to several in number) before striking
the target. Only through experience and dedicated training
can a Ninja learn to estimate distance and judge how many
rotations or half rotations a knife will need to make in order
to strike a target point first. Remember that knives thrown
by the handle must execute whole or complete spins (1,2,3,4,
5,6, etc). Knives thrown by the blade must execute a number
of half spins (l/2,1%, 2%, 3%, 4X, i%, 6X, etc.) Once the basic
theories and principles listed in this section have been
learned, the Ninja must establish an effective training
program.