The Spurs and Trail Blazers will open their first-round series Sunday night in a matchup the betting market views as one of the most lopsided on the board.  San Antonio is a 10.5-point favorite in Game 1 over Portland, who enters the postseason as the West’s No. 7 seed after a NBA play-in tournament win over the Phoenix Suns.  The Blazers actually played the Spurs well this season, winning one game in San Antonio and staying close in two others before losing.  There’s just one major issue for