Walberg was not the ace of the Philadelphia Athletics, but he was an active component of a starting rotation and team that would form a mini-dynasty that won three straight American League Pennants (1929-31). The Minnesota native debuted for the Athletics in 1923, and by 1927, he came into his own with a 16-12 season. Walberg would win 17 Games in four of the next five years, peaking with 20 Wins in 1931, the same season he led the AL in Innings Pitched (291.0). He would also help the Athletics win the 1929 and 1930 World Series.He would decline after the 1931 season and be traded to the Boston Red Sox after 1933. Walberg would have a 134-114 record for the Athletics.