I've had the pleasure of watching Efren practice rotation on numerous occasions at Hardtimes. One time he ran down to the 10 ball getting perfect on every shot, before switching his cue back to his RIGHT hand to finish out the rack. He made it look so easy we didn't even notice we was shooting lefty the whole time.
Another time he got stuck on maybe the 6 or 7 ball being blocked to a pocket by another ball. He looks at it for about 15 seconds, then jacks up his cue and jumps the object ball over the impeding ball. Cue ball hops up and stops dead for shape on the next ball, where he then proceeds to run the remainder of the rack.
Another feat I've seen Efren accomplish is playing straight rail billiards on a regular pool table, somehow nursing the balls in the corner without having any of them fall in the pocket. When he got out of position he'd hit some crazy shot and have the balls end up in another corner where'd he do it over again. Efren would also practice rolling shots from all over the table so the object ball would stop at the lip of the pocket without actually falling in. Watching Efren practice is like watching a magic show but none of the tricks are pre-planned.