And I play other sports involving spinning balls well enough to understand how a ball behaves when it's spun. If you know how the ball is spinning, you can predict its behaviour in the air and off the wicket. Just because Shane Warne has bowled it, it won't behave any differently if spun the same way by anyone else. This article is going to be long, and at times have the tone of a mechanics lecture. Unfortunately, to achieve a complete understanding of, for example, why a top-spinner does what it does, this is necessary.
Lets start with the basios.
Speed and Velocity People often use these two words interchangeably. They aren't, not quite. Speed is a simple measure of how fast a thing is going, expressed as so many units of distance per unit time. It's also possible to refer to an object's speed in a certain direction. This is usually called the component of the object's velocity in that direction.