Complex sentence: The 2016 NFL season, the 97th season in the history of the National Football League (NFL), began on September 8,2016, with the defending Super Bowl 50 champion Denver Broncos defeating the Carolina Panthers 21--20 in the NFL Kickoff Game.
Split into simpler sentences: The 2016 NFL season was the 97th season in the history of the National Football League (NFL). The season began on September 8,2016, with the defending Super Bowl 50 champion Denver Broncos defeating the Carolina Panthers 21--20 in the NFL Kickoff Game.