I was watching a match the other day and Efren got a little out of line, as below. Due to impeding balls around the table, going 3-4 rails around for position was not an option. It was a ring 10 ball game so safties were not allowed either and he had to go for the shot. Billy Incardona said the key to getting position was to jack up the butt and hit with low inside english. Billy stressed that Efren must jack up to get position off the top rail. What does jacking up do to the cue ball as opposed to hitting with a level cue? I'm just trying to learn something.