How to throw a sinker are pitches that have a downward movement. They are used by pitchers who want to keep hitters guessing. These pitches are similar to the fastball, but the movement is much slower. The main difference is the use of the index finger, which is parallel to the seams. The follow-through should also be similar to a fastball. Pitchers should avoid placing extra pressure on the middle finger, which adds extra spin to the pitch, causing it to drop as it crosses the plate. Sinkers have a lot of incidental horizontal movement.