Diagram 3: Triple line drill
Young dogs sometimes develop a tendency to go back to the last place where they picked up a bumper. The triple line drill can be used to counteract that tendency and to refine your retriever's skill in taking a line. A large field with relatively light cover is the ideal setting.
These retrieves should be undertaken on a step-by-step basis. First, handling your dog from Point A, do two repetitions of a sight blind planted at location X1. Next, handling your retriever from the same spot, do two repetitions of a sight blind planted at location X2. Third, send the dog on two repetitions to a sight blind planted at location X3. After completing those six tasks, vary the order of six additional retrieves.
If your dog takes off for a retrieve other than one for which you lined him up, stop the dog with the whistle and cast him back to the proper line, or call the dog back and start over. Make sure the dog understands your lining instruction.
As your dog progresses and is consistently retrieving bumpers after being released from Point A, you can move back 10 yards to Point B. When the dog accomplishes retrieves from that position, move back 10 more yards to Point C and, finally, to Point D.
This should not be undertaken in a single outing. Also, keep in mind that since the dog will be running longer distances as you move from Point A to B, take a little longer between retrieves to let the dog catch his breath. Be careful not to overdo this drill in warm weather.