I rarely shoot autofocus for action stuff. I guess the exceptions would be motocross and bmx racing — Stuff that is totally unpredictable, but even for that stuff I pre-focus quite a bit. If it’s a shot I set up, it’s almost always manual pre-focus, meaning have the rider stand there, or focus on something the same distance as the action. Then you know your stuff is sharp. Even good autofocus is unpredictable. Something like that LG event where I’m moving around a lot, sometimes I’ll shoot some stuff with focus tracking but then it can be hit or miss. That snow rail contest for instance, I would reset my focus every time I moved to a new spot, so I was shooting manual focus, and if it was new angle, setting a new focus, and then shooting again. A shot like the photo of Chad above was done by pre-focusing. I knew where he was going to be, so I set up flashes, focussed on that distance, and that way knew it should be sharp. With anything there are exceptions I guess, but I’m manual pre-focussed most of the time.