This is the third of a 3-part series on using sidespin. When you shoot with sidespin, there are three elements that can affect your line of aim: squirt, swerve, and throw. These effects are more noticeable at longer distances and with faster stroke speeds. Due to the inconsistencies of using sidespin, only use sidespin when absolutely necessary!
Sidespin can change the angle of the object ball in the direction of the spin due to the friction between the balls. The diagram below shows right spin causing the object ball to be thrown to the left — as seen from above.
Throw can be increased with more sidespin (up to a point), a fuller hit on the object ball, and a slower cue ball speed. This type of throw is called "spin-induced" throw, as the spin of the cue ball grabs the object ball and changes the angle.
There is no guaranteed system for compensating your aim for throw, so the best method is to PRACTICE! Use the shots in Bullseye Billiards to systematically understand how swerve works for various tip contacts, stroke speeds, and your equipment.
For more information on throw and aim compensation, visit Dr. Dave's Billiard Resources page.