Billy Horschel explains the mental approach he’s taking into Round 4 at Royal Troon, where he’s the 54-hole leader in The Open Championship. #GolfChannel #TheOpenChampionship #BillyHorschel » Subscribe to Golf Channel: https://www.youtube.com/golfchannel?sub_confirmation=1 » For the latest news around golf: https://www.nbcsports.com/golf…