Reliability of radar guns?

I’m beginning to think radar guns and velo numbers are witchcraft. My son has been on a variety of different guns and apparatus that measure his velocity for the past 2 years. I have seen numbers from radar guns from behind home plate, guns off to the side, at an angle, from behind, and a baseball with an accelerometer in it.
The numbers have been everywhere. The highest numbers coming from the guns behind home plate and the accelerometer ball. Lowest from the side and angle, guns. Not sure what to believe. The one true stat is the reaction of the batters.
Numbers are numbers, but the wide range is mind boggling.

This is a great question. Radar guns can only get the true velocity when they are used correctly and are aimed directly in-line with the path of the ball. As you get off to the side this adds a significant angle between the radar beam and the path of the ball. This will cause any radar to read a lower speed due to the Cosine effect. Also, accelerometers in a ball do not work the same as a radar gun so the readings will not be as consistent. If you want to understand more about how to make sure you get accurate readings from a radar gun you should check out this series of blog posts where someone goes over all of the things that are important to get a good reading:
If you ever have any questions on anything related to radar please give us a call on our toll-free support line at 888.381.2672 weekdays from 9 AM to 5 PM Pacific Time. We are always happy to help.
Chris Stewart / President, Pocket Radar Inc.

Hi speed camera in your smartphone and a slow motion app. Time it and do the math, gives you the average speed to home plate but very consistent.

In a competition a kid was throwing mid 60s and jumped up to mid 70s just because he threw a high fastball. Only pro guns you can trust.

You are right, you need to be careful to understand the accuracy of the radar gun or other technology being used. It is interesting that no one ever seems to go out and check the accuracy specifications on even the expensive radars. There are only a couple of brands that are in use by the pros at MLB for a reason. It is also very important to understand how to set up the radar correctly. All radars must be set up very carefully to get good readings. Zac Morain (with Driveline Baseball), did a three part series called “Radar Gun Fun” that tests various radar guns from the most expensive to the cheapest and shows the variations. He also goes over all of the the things that can cause issues with radar gun readings. Take a look at this link:
If you ever have any questions about how any radar works and what you can expect we are happy to help. You can reach us on our toll-free support line at 888.381.2672 weekdays from 9 AM to 5 PM Pacific time. Thanks,
Chris Stewart / President, Pocket Radar Inc.