I think Josh Gibson has always been considered the best offensive catcher in baseball history and the best offensive player in the Negro Leagues. I don't know how you would go about comparing Gibson's Negro Leagues statistics to Mauer's, except that Gibson had a very long career as a catcher and Mauer will never have that chance. Bench's accomplishments were primarily about being a catcher, his career was cut short because he was a catcher and he lead one of baseball's best teams (which he was lucky to be on) so it is difficult to compare him to Mauer. Mauer will probably go up the list of all-time greats at another position so the Twins can protect their biggest investment ever. Bench was quickly worn down behind the plate at a time when all players were expendable. "Bench won the 1968 National League Rookie of the Year Award, batting .275 with 15 home runs and 82 RBIs, marking the first time the award had been won by a catcher. He also won the 1968 National League Gold Glove Award for catchers, marking the first time the award had been won by a rookie.1970 was Bench's finest statistical season; he became the youngest man to win the National League Most Valuable Player Award, hit .293, led the National League with 45 home runs and 148 Runs batted in, and helped the Reds win the National League West Division." http://en.wikipedia.org/wiki/Johnny_Bench