Complex sentence: The Pro Football Writers Association is a poll of its more than 300 members and the editors and writers for Pro Football Weekly and Sporting News's All-Pro team was determined through voting by NFL pro personnel directors.
Split into simpler sentences: The Pro Football Writers Association team is from a poll of its more than 300 members and the editors and writers for Pro Football Weekly. The Sporting News's All-Pro team was determined through voting by professional NFL personnel directors.