Just to add to my earlier post, you end up with
rate = distance/time
Where rate is your speed.
Make sure your measurements are all in sync though, by this if you having the time in seconds, and your distance in yards, you'll get a weird looking speed
So you may want to convert the distance to miles or kilometers before calcuating the final total. For the record 22 yards is about 0.0125 miles. So say it took .75 seconds for the ball to get from your hand to the stumps.
You'd have .0125 / .75 = 0.016666*
Now multiply the .016666 with 3600 to get a time based in hours instead of seconds and you get 60mph.
Bare in mind this is not perfect, and my maths is a little rusty, so hopefully anyone who is currently studying maths or physics can correct me If I am wrong