I guess I could understand it in college ball since foul territory is larger than most of the fields we play on. The only time I would even consider this with the catcher is on a play by the second baseman or a DP attempt when the throw is coming from second base itself. If the throw is coming from shortstop, third base, or the pitcher, IMO the right fielder is better suited to back up first. That said, we do not teach this with our team.