Emery Ball (Scuffball)

aka scuffball · scuff ball · emery board ball

Illegal since 1920. One side of the ball gets scuffed rough with sandpaper or a hidden sharp edge, and the rough patch throws the air off balance so the ball swerves in ways a clean ball never would. Outlawed, and scuffing the ball is cheating.

Schematic baseball cover. This pitch has no filed seam geometry yet — the grip and shape below are sourced in words, not measured here.

The grip

One side of the ball is roughened — scraped with emery paper, an emery board, sandpaper or a hidden sharp edge — to create a deliberately rough patch on an otherwise smooth ball.

Reputable analysisSpitball — Wikipedia (saliva/Vaseline mechanism, 17 grandfathered pitchers, Grimes 1934, Perry)

What it does

The abraded, rough side disrupts airflow asymmetrically, so the ball breaks toward or away from the scuff in ways a clean ball would not.

Reputable analysisSABR Games Project — August 3, 1987: Twins' Joe Niekro ejected for allegedly scuffing ball (emery board, sandpaper, gouged balls)

What it really is

Banned alongside the spitball on February 9, 1920. Its most famous modern moment came on August 3, 1987, when Twins pitcher Joe Niekro was ejected after umpires found an emery board and finger-contoured sandpaper in his pockets, with the inspected balls showing fresh gouges.

Reputable analysisSABR Games Project — August 3, 1987: Twins' Joe Niekro ejected for allegedly scuffing ball (emery board, sandpaper, gouged balls)

Who throws itRuss Ford, Joe Niekro (alleged)

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.