Speed. Base stealers have it, pitchers throw with it, and with the advent of StatCast – batters can have it too. Exit speed is a measurement of how hard a given ball is hit as it leaves the bat. The higher the exit speed, the farther a ball has the ability to travel.
The measurement of speed in baseball is nothing new – in the 1960’s radar technology enabled scouts to measure pitch speed as the ball left a pitcher’s hand. Exit speed, however, is a much more recent development. When StatCast went live throughout MLB parks in 2015, fans were introduced to this metric for the first time.
In the Rapsodo hitting app, exit speed can be seen in the top left of the display after a ball is hit. The number in the middle is the exit speed of the most recent ball hit, and the ring surrounding the number a representation of the ball’s speed out of 100. The other two numbers displayed are “Max”, the player’s max exit speed from the session and “Avg”, the player’s average exit speed from the session.
Performance – What’s good?
Average Exit Velocity by Age
It’s common sense to understand that a higher exit velocity is a better exit velocity, but what’s a ‘good’ exit velocity? That depends largely on your age and skill level: 
Coaching
Exit velocity, especially a player’s max exit velocity, can be used as a good measure of raw power. While it may not show up as much in game, a player with a higher than average max exit velocity for their age likely has untapped potential. Exit velocity is far from the most important thing about a player, as other skills like contact ability and eye are crucial, but a hitter will not advance in baseball without an exit velocity near their peers.
