AVERAGE SPEED and maximum speed are two different things....a device like a RevFire calculates average speed, while a radar gun give maximum speed. You can use either for developmental purposes, but if you want to brag to all your friends about how fast your DD throws, you will want to use maximum speed...
Calculating pitch speeds from video
- Thread starter robinh
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AVERAGE SPEED and maximum speed are two different things....a device like a RevFire calculates average speed, while a radar gun give maximum speed. You can use either for developmental purposes, but if you want to brag to all your friends about how fast your DD throws, you will want to use maximum speed...
As [MENTION=5663]JAD[/MENTION] stated pitching velocity is typically measured as peak (maximum) speed. Beyond that if you have maximum speed and terminal speed you get a good idea of spin rate (air resistance). As to calculating air resistance that is not possible without spin rate.
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Do you wear a pocket protector at work???
I calculate speed regularly off of video. I find it to be pretty darn accurate and takes away all the jugs v. bushnell v. pocketradar arguments. Video if shot from a reliable angle will not lie. It's not that inconvenient once you have a spreadsheet either.
Just make sure you account for release point this is easy to do if the circle is there. Also account for the ball position on the last frame, @30fps it's usually ±2 feet from the measurement point on the plate (easy enough to approximate).
Don't get too hung up on speed. Unless your pitcher is ahead of the curve and over powering batting lineups, a high rev rate or even off-speed pitching can do much more damage than an average pitch speed.
Just make sure you account for release point this is easy to do if the circle is there. Also account for the ball position on the last frame, @30fps it's usually ±2 feet from the measurement point on the plate (easy enough to approximate).
Don't get too hung up on speed. Unless your pitcher is ahead of the curve and over powering batting lineups, a high rev rate or even off-speed pitching can do much more damage than an average pitch speed.
- Nov 18, 2013
- 2,258
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My math and physics skills are fuzzy so please help me understand. If we have two girls we know are both throwing 60. One releases 35 ft from the plate and the other 36 ft. Wouldn’t that give two different totals if we’re using a formula and video? If so, how significant would that 1 ft be?
It depends on how you are measuring. With a RevFive, which measures the time from release to catch, the shorter throwing distance would produce a faster reading. If someone is using slow motion video and just measuring the time to travel a shorter distance then it should not effect the results. BUT, as I mentioned in a previous post. Any time/distance measurement to calculate velocity will produce an average velocity, not a maximum velocity.
If you really want to see your DD's eyes light up, set the RevFire to 35' when your DD is throwing from 43' and check the results. It is almost as good as "Radar Grandpa"...
longball00
Softball is my obsession
So which is a better device for true accurate speed, the Rev Fire or the Pocket Radar. From my experience they are around 4 MPH different.
RevFire is average speed and Pocket Radar is maximum speed...and the RevFire is easy to fool by changing the distance thrown.
- Jul 5, 2016
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Assuming speed at the point of release is 60 mph and assuming no loss of speed, there will be about 1/100th second difference in travel time to the plate. The ball is traveling at 88 feet per second. However, the ball will lose approximately 1 mph of speed for each 7 feet of travel so the pitch released from 36 feet will be going slightly slower when it crosses the plate - in theory, 55 mph versus 54.86 mph.
The physics of it all are pretty complicated to say the least. The article below explains it.
http://0314c3a.netsolhost.com/wordpress1/wp-content/uploads/2012/05/BALL-SPEED-SLOW.pdf
