Just a helpful hint, move faster and move with purpose because you are boring your dog to death. It's very hard to maintain focus when you are boring. Just picking up the pace and moving like you have somewhere to go will keep your dog's attention much better.
Also, don't wait for your dog to turn. If he doesn't make the turn with you, he gets corrected. It's also confusing for him to figure out if your slow turns - yes, I said your turns - are turns or sits, so he just stands there to see what you are doing.
Elaine and the herd