Rule 2 - Limit the number of dogs playing at any given time to 2 or 3. Any more than this is tough to supervise and results in fights. Rule 3 - Limit each game to no more than a couple minutes. The dogs get extremely excited and you can not believe how exhausted they get. Rule 4 - Do not play in very hot weather.
Dogs have a limited ability to dissipate body heat.
This game involves extreme exertion and can be dangerous in the hot weather. If the weather is too hot to leave your dog in the car, then it is too hot to play this game. Never leave the dogs unattended with the tetherball in place. To do this is to ask for disaster. The game is fun and safe when supervised, but like many things is dangerous when ignored.