Complex sentence: The Brooklyn Dodgers, although under the General Managership of Dodgers (baseball) legend Jackie Robinson, failed to attract at the gates and so the franchise became a league-operated "road club" early in the season.
Split into simpler sentences: The Brooklyn Dodgers, although under the general managership of the baseball Dodgers legend Jackie Robinson, failed to attract at the gates. The franchise became a league-operated "road club" early in the season.