Hey Low,
I designed and built them with that "issue" in mind. There were NO
such incidents last year. When kids play, I strongly suggest they start
at mid-point. Then there's the drunks...
Seriously though, I deepened the pits with at least 8 inches of sand to
reduce the bounce and extended the side which ate 18" tall and they
project out 4' from the back stop.
That being said, when Murphy's around, he's around.