Thanks guys..I was explaining to a friend in another forum so rather than rewrite, I will post what I sent him:
"It's freaking amazing I could get any sharpness at all. There is no warning, other than I think a nod by the rider she/he is ready, but the time between the nod and the release can be up to 10 seconds. It is the release guy (the middle guy in the other shot) who decides when the rider and the bull are peaked for performance...it's kind of like the flag guy at Indy, Le Mans, etc.
So you have to be constantly at the ready as in most cases you can only see the rider through the lens. I learned years ago in high school to shoot with both eyes open especially when shooting telephoto lenses, so I can do this probably more easily than the averge joe/jane. Even so, it almost always catches you by surprise for the first second. In that first second they go from deep in the release pen to half way out. The pen is about 25 feet deep, ten wide.
I found this rodeo stuff to be particularly exciting and there's always something going on or a person of interest to be found in a readied lens."
In this shot, the two guys on opposite sides of the rider are the release guys. I wish I'd used this DOF on most of the other shots as I think the isolation factor really works well. I'm stoked and ready for more!