Complex sentence: Tom was one of three brothers to play in the Majors; younger brother Jim played for the Milwaukee Brewers in, while older brother John played one game for the Houston Colt.45's (where he went 3-3 and walked twice) in.
Split into simpler sentences: Tom was one of three brothers to play in the Majors. His younger brother Jim played for the Milwaukee Brewers in, while older brother John played one game for the Houston Colt.45's (in which he went 3-3 and walked twice) in.