it works, it's not a theory. . . granted, you wont be 100% and still it does take practice and somtimes, especially if you dont have the right light, you dont have enough shutter speed, but if you do, it's the best way to shoot that kind of speed. I've been shooting horse races and rodeos for years and even with the best equipment money can buy, I still prefocus if I know the action is too fast for the lenses or my predictive skills. . . It's even eisier when you know, for example, the dog is going to in the box and you can time the jumps based on the prior jumps.

In any event, it just was a suggestion since almost anyone with a camera can have a chance at a good image of actionn, now and then by prefocusing, in fact you dont even need a fancy lens to take great images, as long as you get the timing right on the dog leaps and have enough light, it will work.

I'd use a monopod, but a tripod would be a dream, especially if you dont have to move around.

Nonetheless, it's a great shot no matter what the method. . .

Piece