If you are going to give the good old swing shot a go I'll pass on some advice I got from a fellow pro who specialised in children's photography.
To get the swing shot, don't rely on tracking your subject but carefully place yourself so you get a good clear view of your desired position on the arc of the swing. Focus manually on that point and wait for the swing to hit the desired spot. I tried it in the garden yesterday and it works a treat.
Cracking little lad