Years ago, it may have been Delmar Smith, some guy wrote about this method of staking out dogs. I'm using it now since I have more dogs. It is SO good for young puppies and old guys, to boot. You can see Bo, a veteran of many years of chain gang life, and under him is Cap, on the chain for the first time. I wanted to get a video of him doing flips and whining, etc., but he calmed down very quickly. I really don't know why it works so well to keep the dogs focused- maybe it's because now they are attached to other dogs instead of just thinking about themselves, the individual. It's a very useful tool for the bird dog man. I normally make my own, but this one I bought for $46 at Lion Country.