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Fastball Scouting Terms, Explained

A good fastball has always been about more than just its velocity. How it moves and where the pitcher locates it have always been integral to a fastball’s success. But for decades, radar guns were the only publicly available tool to measure a fastball. Thus, the pitch was often described solely by how hard it was thrown.

The rise of new technologies has led to changes. Now, whereas observers could once see a fastball’s movement but had no way to measure it, the exact amount of movement—in any direction—can be now measured to the smallest decimal points. The same goes for how many revolutions per minute (rpm) the ball averages on its way to the plate, the axes of its vertical and horizontal spin (spin axis) and how well it maintains those axes as it approaches the plate (spin efficiency).

The rise of the new technologies and revelations about the fastball has led to a host of new terms used to describe the pitch and what it does. Here is a quick guide to what each of the terms used to describe various fastball attributes means. Note that not everyone in the game agrees on what differentiates angle and plane, as well as carry and ride. The most common usages of those terms are below, but some organizations use different definitions. Each example is illustrated by a prominent major league pitcher.

Horizontal trajectory of the ball from the pitcher’s hand to the plate. Player to think of? Madison Bumgarner.

Vertical trajectory of the ball from the pitcher’s hand to the plate. Player to think of? Jacob deGrom.

Horizontal movement to the pitcher’s arm side. Player to think of? Charlie Morton. 

Horizontal movement to the pitcher’s glove side. Player to think of? Clayton Kershaw. 

Vertical movement downward. Player to think of? Dallas Keuchel. 

The illusion of vertical upward movement, created by a 12-to-6 spin axis. Player to think of? Blake Snell. 

Often used interchangeably with carry, but sometimes denotes additional late movement. Player to think of? Justin Verlander. 

A combination of ride and run, signifying hard movement up and to a pitcher’s arm side. Player to think of? Jordan Hicks. 

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