Steer stopping with no heeler puts less pressure on your team roping horse in the heading box. The horse relaxes more, and you get him standing there calm and leaving flat. Watch these videos of great steer stopping examples, and then read pages 70-73 in August 2011's STW for the full how-to article on improving your steer stopping.
Steer stopping is a great exercise for you and your horse. Learn how with Travis Tryan.