If you are sending from your side and stopping the dog then you are on single T and not mini T. In mini T the dog should be in front finish facing you and you would go through all the casts making sure that the dog understands each cast and the difference between overs and backs. In this drill you would call back and recast. Have you done this?
Another question...you say when the dog goes the wrong direction. Is the dog turning the right way and digging back? If so just stop with the whistle, tweet in and recast. Is the dog watching you through the entire cast. Some dogs have trouble at this stage because the don't watch the whole cast and go as soon as you move. Casts need to be ultra slow at this point with verbal restraint and emphasis on watching you. All of this should be cleaned up on mini T before moving to single and double T. Don't be afraid to stop the dog. This is where the dog starts learning about attrition. You are forcing on a known location anyway but if done right popping shouldn't develop. You mentioned your dog did better when you moved closer. This is because distance erodes control. Your dog should be about 5 yards in front of you in mini T so this should not be an issue.
Sorry Tony, I called the drill I'm working the wrong name... I'm working the single "T" with him right now, so I guess I should have started on mini t. I have not done the mini "T" yet. He's was doing 1 of 2 things on right overs, he would either turn (the correct way) but try and go on a right back if I sent him on a right over, or he wouldn't move from remote sit (you could tell he was confused about what he needed to do).
I worked him pretty hard on it yesterday evening, I did 2 sessions with about 18 bumpers apiece. I moved closer to gain a little more control, I moved the left and right piles slightly closer to the center line to provide additional visibility, and I really slowed him down when casting while he was in remote sit and exaggerated my motions towards the right pile (taking a few steps over on the first few casts). He's trying to anticipate the cast sometimes it seems, so slowing down seemed to help that issue.
To answer everyone else's question, he wasn't having any trouble on left overs, left backs, or right backs... only right overs.
He did much better the first session, only having a slight bit of trouble on the first right over. After that, I could see it click with him and it was game on after that. He nailed the remaining bumpers in that session and got all of them perfectly on the next session (right backs, right overs, left backs, left overs, and of course the straight to back pile with no stop).
My question now is, since I should have started on the mini-t, should I stop him on the single t and start working him on the mini t, or should I just continue through the single t since I already started? He seems to have it down now.
Thanks for everyone's advice :-)