R. Tarara asks which way curve balls spin and which way they curve.
A right handed pitcher imparts a spin which if viewed from above appears
to be counter clockwise. This causes the ball to break away from a right
handed batter. In reality the spin axis is not vertical and the ball really
breaks down and away. As I recall early editions of Ostdeik and Bord argued
that there would be lower pressure on the side of the ball which was moving
at a higher speed relative to stationary air and that the ball would curve in
to a right handed batter. This section does not appear in more recent
editions of the text.
The Physics of Baseball by Robert K Adair, Harper & Row, $7.95 is a great
little book.