Complex sentence: Many people feel that the Western saddle is more comfortable than the English saddle, a theory that is given creedence because of its history and purpose: as a working tool for a cowboy who spends all day, every day, on horseback.
Split into simpler sentences: Many people feel that the Western saddle is more comfortable than the English saddle. A theory that is given creedence because of its history and purpose: as a working tool for a cowboy who spends all day, every day, on horseback.