Hit a school with a soccer field, and there were coins everywhere. Most of them were pennies, 95 to be exact, however a one and two dollar coin brought up the totals a bit. I was very surprised to get 4 rings on this field. In fact, I only finished about half the field. Two of the rings were in the sidelines. One of the rings was a double colored copper/bronze ring, a bit larger then the same style I dug last week at a different soccer field. It's really amazing how one field can differ from another.
There's a lot of trial and error involved in hunting those sports fields.