When we go out training one important tool that we like to use is the chain gang. There are multiple reasons why we like to use the chain gang. 1st it gets all the dogs in an organized situation so when you want to work a particular dog you can take him out and work him while the others can watch. 2nd it allows you to have control of the dog and the situation, this allows you to teach a dog a few things like not to jump on people, and it also teaches a young dog an association with his collar and lead. 3rd If used correctly like the Delmar Smith method it allows the dog to learn that it has to hold still before you take if off the chain and when you introduce the checkcord the dog will associate the tug from the cord like the tug from the chain. This will help the dog realize a lot quicker what you are asking the dog to do. These things may seem small but pay huge dividends down the road when your working the dog on more advance training like whoa.

Bird Dogs On The Chain

Here is an article with some more information about the chain.

http://www.outdoorlife.com/blogs/gun-dogs/2010/07/stakeout-chain