Alot of new people, well, people in general do not beleive in putting a dog on a chain. My input is, if you have only one dog, keep him inside, if you have more than one, put em on a chain.
I dont mean that as in just a chain, my setup is half chains and the other half 20 ft. kennel runs.
I DONT beleive in using monter size chains, there just no reason. Put a nice size chain that your FOR SURE will hold your dog and stick with it.
The Pit Bull Blog 
My only question in response to this is, Is the dog mean because he is on a chain?, or is he on a chain because he is mean? I have 4 large 50 – 85 lb mixed breed dogs, 4 breeder pitbulls 45 – 83 lbs and a 17 week old pitbull puppy, plus 7 cats that are all in my house. I let them in the house so that they are better socialized with people and other animals. They have a large fenced in area outside to run and play in as well as go potty. my wife and I raise and breed pitbulls as family pets. they are not raised to fight. If you chain a dog up and don’t socialize it with people or other animals, you are asking for trouble later. A well socialized dog, is a happy dog.
Ya I dont agree with chaining. My pit is in my house as a family member, and when outside she is loose in a big fenced yard. The chain, or rope as it is, is only a punishment method that I use. It works quite well actually!