Banned & doctored
Shine Ball
Illegal since 1920. The opposite trick from the scuffball: one side gets polished slick instead of roughed up. The smooth-versus-rough contrast bends the air and gives the ball surprise late movement. It was banned along with the other doctored pitches.
The grip
One side of the ball is polished smooth — Eddie Cicotte rubbed it against a trouser pocket loaded with talcum powder (and, by one account, paraffin) — leaving the two sides of the ball with sharply different surfaces.
What it does
The smoothed, slicker side creates an airflow asymmetry against the rougher side, producing unexpected late movement.
Period accounts credit the shine ball's break to the polished-vs-rough asymmetry; the precise aerodynamics were not measured in that era, so the mechanism is described as understood by contemporaries rather than instrument-verified.
What it really is
Associated above all with White Sox ace Eddie Cicotte, who developed it in 1917. AL president Ban Johnson ruled it legal that year, and it stayed legal until the February 1920 ban swept up the shine, spit, mud and emery balls together.
Who throws itEddie Cicotte
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.