I take thousands of football action shots on the field. I used BBF many times but found the action, distance and framing changes so fast I would be constantly pressing the BBF. The new cameras have internal focus program settings designed to follow action, catch sudden zigs and zags and action just coming into the frame which are so much faster than manual. I recently went to the Canon 1dx which can fire 14 shots per second and there is no way I could possibly BBF that fast. At a recent game in Giants stadium I used a Nikon D810, usually use for portraits and travel shots not sports, with a 500 mm zoom and found the auto focus was slow until I re-set the focus program and was then able to get those fast action shots. The BBF would have worked as I was not taking high speed action but singles. I think the camera is way faster and adjusts much more quickly than any human at this point. Older cameras might be better to use the BBF. BTW I always use shutter priority, 800-1000+) for sports unless I'm trying to get a certain effect and the newer cameras are designed to set the ISO for low stadium lighting.