pitch speed measurement: math vs radar gun

[FastPitchCat]

happy 2014!

what's a more accurate way of determining pitch speed? I've tried a bushnell radar gun and wasn't too sure if that was more accurate than good ol' math.

mathematically, pitch speed would be:

(pitch distance)/ballTravelTime * 3600/5280
where 3600=seconds in an hour and 5280 = feet in a mile

i measured DD's pitch yesterday (yes, last pitching session before the new year) at the point of release to catcher's glove at home plate. 43 - 5 + 3 where 5 is the stride distance and 3 is distance from catcher's glove to home plate.

(43-5+3)/0.52 * 3600/5280 = ~53 mph.

there's of course a slight inaccuracy as when to start the timing during ball release and when to stop timing when the ball reaches the catcher's glove.

i think that measuring this way is getting the average speed, while radar gun is instantaneous.
is this right?

 

[sluggers]

i think that measuring this way is getting the average speed, while radar gun is instantaneous.
is this right?

That is correct.

 

[JAD]

Cheap Radar guns may be off a MPH or two, but they are usually consistent if used properly, and can be a good tool to gauge your DDs progress.

 

[lhowser]

Have you used video and counted the frames. (30fps).

 

[lhowser]

happy 2014!

what's a more accurate way of determining pitch speed? I've tried a bushnell radar gun and wasn't too sure if that was more accurate than good ol' math.

mathematically, pitch speed would be:

(pitch distance)/ballTravelTime * 3600/5280
where 3600=seconds in an hour and 5280 = feet in a mile

i measured DD's pitch yesterday (yes, last pitching session before the new year) at the point of release to catcher's glove at home plate. 43 - 5 + 3 where 5 is the stride distance and 3 is distance from catcher's glove to home plate.

(43-5+3)/0.52 * 3600/5280 = ~53 mph.

there's of course a slight inaccuracy as when to start the timing during ball release and when to stop timing when the ball reaches the catcher's glove.

i think that measuring this way is getting the average speed, while radar gun is instantaneous.
is this right?

What was the difference between the two and how many did you consistently measure at 53?

 

[JAD]

Have you used video and counted the frames. (30fps).

Any type of timing device used to measure pitch speed (stopwatch, RevFire, counting frames) will give an average speed, while a radar gun should give you the maximum speed, which occurs right after the pitch is released, when done properly. Those two numbers could could vary by several MPH and both be technically correct.

Please note that I say "when done properly".....someone needs to provide a link the the YouTube video of Grandpa clocking his DGD by "stabbing" the radar gun at the pitch in case anyone missed it! LOL

 

[FastPitchCat]

What was the difference between the two and how many did you consistently measure at 53?

unfortunately, i don't have the radar gun any more. i found the radar gun reading to vary quite a bit, most probably due to my inexperience in using it. i also tried using the app on my phone where you tap to start and tap to end and it would display the approximate MPH. that was even worse as it depended on how fast your fingers were.


so i turned to video, importing into kinovea and putting a stop watch. again, all is approximate as when i start and stop the stopwatch would alter the numbers.

at least i get a good approximate average speed using this method.

not sure about counting frames. how does one do that? video was taken using iFrame (need to check the fps, probably 30 fps). would frame counting be more accurate than the stopwatch method?

thanks!

 

[lhowser]

not sure about counting frames. how does one do that? video was taken using iFrame (need to check the fps, probably 30 fps). would frame counting be more accurate than the stopwatch method?

thanks!

Seems logically like it would be though I haven't done it myself. It would be average speed. One time someone here on the forum actually developed a spreadsheet for it!

I came up with this formula and plugged it into a spreadsheet. Speed in Feet/Second = Distance in Feet/(Elapsed Frames/Video Frame Rate in frames per second.) Speed in MPH = Speed in FPS * 0.681818181818182, so that is added to the formula to convert the result to MPH.

This formula obviously calculates the average speed over the entire flight of the ball, so I did a little research and found that a softball loses 1 mph for every seven feet it travels. I added a line to the spreadsheet that uses that to calculate the speed at the release (Average speed in MPH + ((distance in feet /7)/2) = speed at beginning of flight.)

I loaded the video on my PC and counted frames pitch by pitch. I have Adobe Premiere which makes it easy to count frames, but you can do it in Quicktime or Windows Media Player, and probably most video players.

I found I could even count fractions of frames, it was obvious when the ball only traveled half the distance in the final frame that it had been traveling in previous frames. I rounded to the nearest half frame, I figure that's plenty precise enough for my purposes.

The spreadsheet allows me to enter any distance and frame rate, then it's very simple to plug in the frame count of a pitch and see the average and top speed for the pitch

Any flaws in my logic or formulas here?

I apparently can't attach the spreadsheet here, but I will be happy to email if anyone wants to try it or check my math. (request it at robin@robinhickman.com)

 

[starsnuffer]

Usually most parents calculate speed as the highest number they've ever seen on the gun whilst shoving the gun towards the pitch and then adding 5, so I think you're on the right track.

Different devices measure the speed differently.

Measuring speed with a rev-fire uses the same method your math uses, it measures average speed from release to glove pop..

Measuring speed with a glove radar (which has a very short range) will measure speed only 3 feet in front of the glove, which is when the pitch is at its slowest point.

Measuring speed with a pocket radar or bushnell gun will generally give you the speed at its highest point, which is when the ball is released.

More expensive guns will trend the speed over the course of the pitch and report based on how the gun is configured, be it highest speed, lowest speed, average, ect.

The important thing to remember is that measuring speed is a training tool. So long as you measure the same way each time, you can spot trends and provide useful data.

-W

 

[FastPitchCat]

The important thing to remember is that measuring speed is a training tool. So long as you measure the same way each time, you can spot trends and provide useful data.

-W

SSN,

i think you bring up a good point here. as long as the methodology is the same, the speed delta should be accurate.
i'm going to try the frames per second method, using the 300 fps mode of my video cam.

thanks!