Complex sentence: Chicago had finished its regular season on November 28th, winning the Western Division with an 8-1-1 record, then sat idle for three straight weekends while the Eastern Division teams settled on a champion.
Split into simpler sentences: Chicago had finished its regular season on November 28, winning the Western Division with an 8-1-1 record. However, the Bears had to wait for three straight weekends while the Eastern Division teams settled on a champion.