Mariano Rivera Joins HoF-Contender Ballot Mailed Out This Week COOPERSTOWN – The Baseball Hall of Fame’s ballot for next year’s Induction is being mailed this week to the 400 voting members of the Baseball Writers Association of America. It includes pitcher Mariano Rivera among 20 new candidates. Others include pitchers Roy Halladay and Andy Pettitte; infielders Todd Helton, Michael Young, Miguel Tejada and Plácido Polanco; and outfielder Juan Pierre will join 15 holdovers from the 2018 balloting Candidates must be…