Reply to "stop watch timing"

Here's an approach that is nowhere as convenient or precise as a radar gun, but it will work if you are careful. You'll need a video camera, a tripod, a bright day, and marks on the ground near the pitching rubber and the plate. You'll also need a way to display the video frame by frame. Some analog cameras have single frame advance playback capability; otherwise you'll need a digital camera and software to do single frame advance playback. It will be easier if the camera has a "sports" mode or the possibility to use short exposure times.

The basic idea is that video cameras take 30 frames per second, and that allows us to measure flight times much more precisely than using a stop watch. It also takes out most of the human element in measuring the time.

Set up the camera on the tripod perhaps 100 feet away from a line between pitcher and catcher, and at the same distance to both. In math class terms, put the camera on the perpendicular bisector of a line between F1 and F2, and about 100 feet away. You want the space between F1 and F2 to fill up most of the sideways field of view of the camera. The camera needs to see the ball in flight and also the rubber and the plate, or markers close to them. We'll need the distance between the rubber and plate or the markers measured to an accuracy of a few inches.

Take some video, and in playback look for the first frame after the ball has left the pitcher's hand, and the last one before it is caught. Measure the distance between the ball's position in these two frames, using the rubber/plate/markers as a gauge. Shorter exposure times and brighter days will yield less blurring of the images of the ball, but just use the center of the blur as the location for a particular frame. You can calculate the average ball speed in feet per second by counting the number of elapsed frames, multiplying that by 0.0333 seconds/frame, and dividing that into the measured distance that the ball traveled between the the frames. For a pitch which travels at an average of 75 mph, or 110 feet/second [conversion is mph times 5280/3600 equals feet per second], the ball will travel 1 foot per 9 millisconds, or a little less than 4 feet per frame.

Depending on when the pitcher released the ball in relationship to the acquisition time of the camera, you might find that the first frame picks up the ball 2 feet from the pitchers hand, and the last frame has the ball 3 feet from the catcher's mitt. Those distances aren't important. Instead the distances between the ball and the plate/rubber or the markers is what allows you to measure the distance traveled during the 14 or 15 elapsed frames.

Once you've got an average speed, add 3 mph to get a speed equivalent to a radar gun.

If you are measuring your own son, add 10mph to match a gun with daddy settings.

With care, you should be able to get within 1 mph of the average speed, assuming you can measure the distance the ball travels to within 8 inches or so.