Complex sentence: A training ground for several players and officials who later established careers in major league baseball, the team proved a formidable regional competitor, winning the 1906 league championship before its dissolution in the months leading up to the 1907 season.
Split into simpler sentences: A training ground for several players and officials who later established careers in major league baseball, the team proved a formidable regional competitor. It won the 1906 league championship before disbanding in the months leading up to the 1907 season.