A majority of shots can be made without sidespin, or
English, on the cueball. Three problems arise when hitting the cueball off
center right or left. One is "squirt," which causes the cueball to travel
slightly off line in a direction opposite of the English. Another is that
a cueball with sidespin will throw the object ball off line because of the
friction between the two balls during contact. The third problem is that
unless your cue is exactly level, the cueball will curve slightly on its
way to the object ball. All three factors make it much harder to hit an
object ball accurately.
On the other hand -- English is essential on some shots in order to
send the cueball into position for the next shot. Use as little
as possible... there's no point in getting perfect position while missing
the shot. Sidespin has little effect on the angle the cueball takes off
the object ball, but it can greatly change the angle at which the
cueball rebounds from a cushion. What affects the angle the cueball
takes off the object ball is topspin (follow) and backspin (draw),
which I'll discuss next time.