<page_title> List of Major League Baseball annual ERA leaders </page_title> <section_title> American League </section_title> <table> <cell> Lefty Grove† <col_header> Leader </col_header> </cell> <cell> Lefty Grove† <col_header> Leader </col_header> </cell> <cell> Lefty Grove† <col_header> Leader </col_header> </cell> <cell> 1931 <col_header> Year </col_header> </cell> <cell> Lefty Grove† <col_header> Leader </col_header> </cell> <cell> 2.06 <col_header> ERA </col_header> </cell> <cell> Philadelphia Athletics <col_header> Team </col_header> </cell> <cell> Lefty Grove† <col_header> Leader </col_header> </cell> <cell> Lefty Grove† <col_header> Leader </col_header> </cell> <cell> Lefty Grove† <col_header> Leader </col_header> </cell> <cell> Lefty Grove† <col_header> Leader </col_header> </cell> <cell> Lefty Grove† <col_header> Leader </col_header> </cell> </table>
Lefty Grove led the American League in ERA nine times, with a career single-season low of 2.06 for the 1931 Philadelphia Athletics.