In baseball, the palmballpitch is a type of changeup. It requires placing the baseball tightly in the palm or held between the thumb and ring finger and then throwing it as if throwing a fastball. This takes some of the velocity off the pitch, intending to make the batter swing before the ball reaches the plate.[1]
Second on the All-Time saves list, Trevor Hoffman, made his palmball changeup his "out" pitch.[2]
One of the more recent pitchers to utilize a palmball consistently in their repertoire is Taiwanese pitcher Chih-Wei Hu, who pitched for Tampa Bay Rays from 2017 to 2018.[3]
The slip pitch was a similar pitch taught by Paul Richards to many young pitchers throughout Richards' career. As it is very similar to the palmball, slip pitch and palmball are often used interchangeably.