Joe Mauer, who enjoyed a six-year peak as one of the greatest catchers ever but spent the remainder of his career as a below-average first baseman, was elected to the Baseball Hall of Fame on Tuesday. Mauer’s name was on 76% of the ballots as he joined Adrian Beltre (95%) and Todd Helton (79%) to form this year’s class that will be celebrated in Cooperstown, N.Y. in July. Players must appear on at least 75% of the 385 ballots submitted by writers with at least 10 years in the Baseball Writers’ Association of America. Mauer’s surprising first-ballot election should signal good times ahead for f…