After spending all but 14 games of the 1907 season in the minor leagues, he played in 102 games in 1908 and by 1909 was a full-time player. That season, he registered a .347 batting average and 67 steals. He would also be named the A's starting second baseman in 1909, a position he would play for the rest of his career, after seeing time at second, third, short, and the outfield the previous two seasons. In 1910, Collins stole a career-high 81 bases, the first American League player to steal 80+ bases in a season, and played on the first of his six World Series championship teams.