In 1900, the National League contracted to 8 teams, and in 1901 the American League joined as the "Junior Circuit" with 8 teams as well. The league remained at 16 teams until 1961.
In a decade dominated by the Yankees and Dodgers rivalry, it is no surprise that Mickey Mantle takes the top spot here, as he is one of the most dynamic all-around players the game has ever seen.
Stan Musial and Willie Mays both put up fantastic numbers over the duration of their career, but looking at just this decade they fell short of Mantle.
There was good pitching depth as well, with one of the maybe three greatest left-handers of all time in Warren Spahn leading the way. Billy Pierce and Bob Lemon were strong contenders as well, but Robin Roberts and Early Wynn no doubt had the better numbers.