Training Tip #37
From: Volume I Training with Mike Lardy
The last step of the Double T is to cast your dog to the various piles when he is returning form the main pile with a bumper in his mouth. I call this "disciplined casting" because the dog must simply take the cast without regard for completing a retrieve. You'll be surprised how easily most dogs take to this, but it may require some coaxing and/or correction to get him to cast with a bumper in his mouth.
Start by stopping the dog at the short crossover in the Double T on his return. Cast him to one of the "over" piles. Repeat the cast or use a little body English to get him going. Soon you will have him casting to the side "overs" or even to the "back"pile. You can use indirect pressure if you get some blatant refusals after you have shown him what you want. If he spits out the bumper, command "Fetch," and then cast again.
The main purpose of disciplined casting is to prepare the dog for the "swim-by" procedure- the next and last step in the yard program. It also prepares your dog for being handled on the return from a retrieve in the field if he tries to avoid water or cover or some other obstacle.