Introducing "back"

Had a quick 10 minute practice today with just the tunnel. Worked on sending ahead and finding the entry. Then introduced a new skill, "back", which means do the obstacle you just did in the opposite direction. So, I sent him to the near side of the c-tunnel, then immediately sent him back in to the far side. This skill would have come in VERY handy at a few gambles where the far side of a c-tunnel was the first obstacle.