At a recent practice, I had my first experience of a blind cross. It was not planned, and boy, was it weird! I had heard of a blind cross but never ran across an explanation of it. It is basically where you turn your back on your dog and lose eye contact.
A blind cross is similar to a rear cross, except that H is asking D to cross behind H, instead of H crossing behind D! I saw this at a trial in Kiln where as D went up the A-frame, H ran ahead and crossed to the other side before D got to the down contact. For a few moments there, D disappeared from H's view because H turned her back on D. In this case, H was reasonably sure D was running down the A-frame, but on the flat, H can not be sure where D actually is.
What makes this handling move happen is when D is running behind H, H is desparate to transition D to the other side, and there is no time for a front cross. So H changes arms in the hopes D will cross over behind H. Didn't work for me.
Training the BC: I suppose the "blind cross" could be trained for, and could come in handy in certain circumstances. Maybe sit your dog, take several diagonal steps forward and away from D, then look over your opposite shoulder and call them to cross behind you for a treat in your opposite hand.
I'll try it and report on how that goes.
Videos: I intended to post a clip here of a blind cross I had videoed in Kiln. I had already uploaded the videos to my Picasa Web Albums and erased from both my camera and computer. When I went to download that particular video from Picasa back to my computer to make the clip, I discovered Picasa doesn't let you download your videos back out of Picasa. What a shock. What's up there is yours to view, but never again to claim! From now on I must store all of my dog's videos on my hard drive. So much for Cloud Computing! Not worth a damn if you give up your right to ever get them back.