Complex sentence: Bumgarner's first word was "ball", and by the age of four, he was already playing in a youth baseball league, for which his father had to sign a waiver because the league was for five-to eight-year-olds.
Split into simpler sentences: Bumgarner's first word was "ball", and by the age of four, he was already playing in a youth baseball league. His father had to sign a waiver because the league was for five-to eight-year-olds.