Martin Hall and Blair O’Neal teach various drills you can do inside the house or office to keep your swing sharp over the offseason. #GolfChannel #SchoolofGolf Download Golf Channel App and watch from anywhere! iTunes: https://itunes.apple.com/us/app/golf-channel/id466053027?mt=8 Google Play: https://play.google.com/store/apps/details?id=com.myleaderboard.GolfChannel&hl=en SUBSCRIBE:…