Off topic, but back in the days of high school gym class we had to walk a few laps around the track everyday to get warmed up. Well, we generally walked one lap and on the way stopped off at the huge pole vault pad/mat thing and performed pro wrestling slams on each other.
Before that, it was just a circle. Didn't need a cage, because no one was leaving it. Ropes on a mat were just so no one accidentally flopped out after taking a hit. Now a cage? What, they're both going to run away?