Complex sentence: After having success in the minor leagues during the early 1920s, Grove became a star with the American League's Philadelphia Athletics and Boston Red Sox, winning 300 games in his 17-year MLB career.
Split into simpler sentences: After having success in the minor leagues during the early 1920s, Grove became a star with the American League's Philadelphia Athletics and Boston Red Sox. He won 300 games in his 17-year MLB career.