Breaking ball
Screwball
A pitch that breaks the 'wrong' way, in toward a same-handed hitter, the opposite of a curve. It's thrown by twisting the wrist backward from how a curve is thrown. One of the rarest pitches in the game, and it has nearly disappeared.
The grip
Thrown with the forearm and wrist pronating the 'wrong' way at release — a right-hander turns the hand clockwise and a left-hander counter-clockwise — the reverse of the supination used on a curve.
What it does
Breaks in the opposite direction of a curveball or slider, moving in toward a same-handed hitter. It is one of the rarest pitches in the game and now nearly extinct; Carl Hubbell and Fernando Valenzuela remain its best-known practitioners.
The SABR source supports the pitch's reverse break, rarity, and Hubbell attribution.
Who throws itCarl Hubbell, Fernando Valenzuela, Christy Mathewson
Study this first
The filed Circle Change fades arm-side in the same direction as a screwball, produced by pronating the forearm at release. The atlas files it as the modern stand-in for this nearly extinct pitch.
Basic file
This pitch has a sourced one-line grip and movement and an honest explanation, not yet a filed specimen with authored grip geometry and a full craft chapter. A fuller breakdown is coming. Sourced, not corrected.
Others in the breaking ball