Sunday in the Park with Dogs

Is there anything harder than getting a good picture of a Jack Russell
terrier chasing a tennis ball?  If you're lucky, you might catch a white blur
streaking across the frame. If you're less lucky, he's moved out of the frame
before you get a chance to click the picture. So, i feel pretty fortunate
to have actually caught these two little Jacks before they went
tearing off across the lawn and out of the picture.