Richard Johnson won the 2018 Gold Cup on Native River, who goes again in Friday’s showpiece raceCheltenham Gold Cup 2019Venue: Cheltenham Racecourse. Date: 15 March. Time: 15:30 GMTCoverage: Live commentary on BBC Radio 5 Live and BBC Radio 5 Live sports extra, plus text commentary, racecards and reports on the BBC Sport website and app.Presenting…