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Pitch Atlas

The lab

Turn spin into shape.

Spin is what gives the pitch its direction. Turn the clock and watch the seam ball and catcher’s-eye plot redraw as ride, drop, arm-side run, or glove-side sweep.

Starting points

Illustrative clock positions, not claims about a specific pitcher.

The ball, oriented to a 12:00 spin tilt. The dashed line is the spin axis.
From the side
Catcher's-eye shape of a custom pitch. Against a spinless ball at center, it rides and stays true. A schematic of direction, not a measured magnitude.RIDEDROPGLOVEARMNO SPIN
Catcher’s eye

Vertical shape

ride

ride, drop, or flat

Side shape

none

arm-side, glove-side, or true

Pure ride. The pitch holds above the spinless path.

Teaching model

A teaching model. Spin tilt sets the direction of the Magnus force: backspin creates ride, topspin creates drop, and sidespin creates run or sweep. This page describes shape only; it does not predict how far any arm moves a pitch.

The plot’s arm and glove sides are named from the ball’s point of view; which physical side that is flips with the pitcher’s hand.