A Note About Pitching Machine Speeds
If a maximum speed of 70mph is quoted for any particular machine, at what distance is it 70 mph?
The distance has nothing to do with the speed.
When we say that a machine has a maximum speed of 70 mph, that is the speed at which the ball comes out of the machine.
When people talk about the speed at different distances, it is important to understand that the machine does not actually pitch a different speed if you are standing closer to it or farther away. What they are referring to is the comparison of the time that it takes the ball to travel different distances at certain speeds.
For example, if you set the machine to pitch 70 mph, and you set it 30 feet from home plate, the pitch will get to home plate in half the time (or "twice as fast as") it would take the same pitch to go 60 feet. Therefore, one could say that it seems like 140 mph at 30 feet, but in reality, the ball still travels at 70 mph.
When calculating the comparative speed between 60 feet (High School and above) and 46 feet (Little League distance), you are really comparing the amount of time that it takes for the ball to go 46 feet rather than 60 feet.
To compare the "ball travel time" of any two distances, divide the longer distance by the shorter distance and multiply the result by the mph. For example, 60' divided by 46' equals 1.30. Multiply 1.30 times 70 mph, and you have 91.
That's why we say that 70 mph from 46 feet equals 91 mph from 60 feet. But remember, the pitch is not actually traveling 91 mph. It just seems like 91 because it is being pitched to you from a shorter distance, so the ball is getting to home plate sooner.