Complex sentence: Douglas L. Allison (July 12,1846--December 19,1916) played catcher for the original Cincinnati Red Stockings, the first fully professional baseball team.
Split into simpler sentences: Douglas L. Allison (July 12,1846--December 19,1916) was an American professional baseball player. He played as a catcher for the original Cincinnati Red Stockings, the first fully professional baseball team.