How to throw a cutter like Mariano Rivera

How to throw a cutter: Usually you hold it like a fastball. The grip is a little bit off of center. Throwing it is like a fastball, and right here at about the release point, turn over your wrist.

The idea is, it's got fastball rotation, and at about 59 feet, it cuts into a righthander for a lefthanded pitcher. For a righthanded pitcher it cuts into a lefthander.

Why is Mariano Rivera's cutter so good? Because it's so late and so quick, and the rotation has such good fastball rotation. It looks fastball to a hitter because you can't see the rotation.