 Mantle and Maris—collectively known as the M&M Boys—are the only teammates to reach the 50 home run club in the same season, hitting a combined 115 home runs in 1961 and breaking the single-season record for home runs by a pair of teammates.Albert Belle is the only player to amass 50 or more doubles in addition to attaining 50 home runs.Prince Fielder, at 23 years and 139 days, was the youngest player to reach the milestone while Bonds, at age 37, was the oldest.