If you ask a coach or pitcher what makes a ball break the common answer is "the spin." Having an understanding of how the spin actually makes the ball move is the key to improving the pitch or designing a new one.

The Magnus effect has been well studied and there are many tools available that will show a pitcher the direction of the spin and the speed of the revolutions. Most of the common tools seem to use revolutions per minute (RPM). I like to use revolutions per second (RPS) but either work equally as well.

In 1692 Isaac Newton noticed that as a tennis ball spins, higher air pressure is built up on one side of the ball and the ball is pushed away from that. In 1852, Heinrich Gustav Magnus studied the relationship between spin and break more carefully hence the name “Magnus” for that type of spin hat makes a ball move. Basically as the ball spins the seams of the ball that are rotating toward the catcher will create high air pressure on that side of the ball, e. g. on the top for a drop ball or on the glove side for a screw. It was noted that if the spin axis was not perpendicular to the line of flight the amount of break the pitch has would be smaller.

Measuring the direction of the spin, or the direction of the axis of rotation, as well as the RPS was long thought (like for 3 centuries) to be the key to understanding movement. Many systems were developed to track those to provide a pitcher a progress report on how the pitcher was doing in improving her spin rate and the accuracy of the spin over time. These numbers could be compared to other pitchers' rates.

Pitchers developed different grips and release mechanics but other than "spin it faster" or "get the direction better" there wasn't much more to do to get more break.

Th most common pure Magnus Effect pitches currently thrown are the drop ball and the curve ball. There are a variety of ways to throw these. The various options available, as well as other pitches where the Magnus effect contributes to the break and Magnus can be found in Developing Magnus Effect Pitches