Los Angeles (AFP) - New England Patriots quarterback Tom Brady is plotting another improbable chapter of his record-breaking career as the National Football League kicks off its 100th season on Thursday.
Almost 100 years after the Dayton Triangles defeated the Columbus Panhandles in what is regarded as the first meeting between two NFL teams, the Chicago Bears and Green Bay Packers will launch the 2019-2020 campaign in a blockbuster season-opener at Soldier Field.
Thursday's kick-off marks the 199th game between the two bitter NFC North rivals, who will play out the 200th instalment of their rivalry at Lambeau Field later in the season.
The Patriots start the season as the team to beat, led by the age-defying 42-year-old Brady in what will be the quarterback's 20th season in the NFL.
Brady completed the 2018-2019 season by winning a record sixth Super Bowl crown as the Patriots shut down the free-scoring Los Angeles Rams in Atlanta.
Once again, Brady will start the season looking over his shoulder at a crop of talented young rivals eager to knock the veteran quarterback and the Patriots off their perch.
- 'Unique situation' -
If recent history is any guide, however, Brady will be relishing the challenge.
Brady, who signed a new contract with the Patriots last month, says his latest arm-wrestle with Father Time represents a journey into the unknown.
"I'm ready to go this year and that's really what matters," Brady said.
"It's a unique situation I'm in. I'm in my 20th year with the same team. I'm 42 years old, so pretty much uncharted territory, I think, for everybody."
After becoming the oldest quarterback to win the Super Bowl last season, Brady could become the second quarterback to reach four consecutive Super Bowls this year.
A successful defence of the NFL crown would make the Patriots only the second team in history to win back-to-back Super Bowls.
Brady, however, heads into the season missing one of his favourite receiving targets following the retirement of tight-end Rob Gronkowski.
However Patriots head coach Bill Belichick has proven time and again that he remains a master of roster manipulation, repeatedly building championship-winning teams despite retirement or departure of key figures.
Gronkowski's decision to quit the sport at the age of 29, meanwhile, and the stunning retirement of Indianapolis Colts quarterback Andrew Luck on August 24, were further reminders of the brutal demands that the NFL makes of its players.
Gronkowski revealed he had known during the Super Bowl win over the Rams that he was probably playing his last win, describing being in tears on the night of the victory as he struggled with pain from a muscle injury.
- 'Unceasing' injury toll -
Luck meanwhile shocked the NFL with his retirement last month, saying he was weary from an "unceasing, unrelenting" cycle of injuries. "The only way I see out is to no longer play football," the 29-year-old said.
Whether Luck and Gronkowski's early retirements are the first sign of a trend of players deciding to hang up their cleats earlier, or an outlier, remains to be seen.
Either way, however, the NFL remains far and away the most watched professional sports league in the United States, even allowing for recent dips in viewing figures.
This season meanwhile may see the patience of fans put to the test, with the introduction of video reviews designed to correct particularly egregious refereeing blunders.
The use of video replay technology has been expanded to cover pass interference calls after a botched call in last year's NFC Championship game between the Rams and New Orleans Saints, which ultimately cost the Saints a certain victory.
Critics fear the expanded use of video replays will lead to more stoppages.