In a Finished level land series, a dog is at the line as a triple is being thrown. The go bird, is a short (15 yrd) mark, that the dog has to pull over about 45 deg from bird #2 in order to mark.
The dog pulls over and sees the mark fall, but stands up as the bird reaches the peak of the arc. Just before the Handler fires the last popper, he says "SIT". The dog sits and waits to be sent following the fall.