The book may close on Tom Brady vs. Peyton Manning this weekend

It’s rare in a game like football that expectations actually pan out.

There are only 16 games to determine playoff spots and seeding. Along the way – and into the playoffs – brute physicality steals stars, leaders, and other impactful personnel from their teams for time spanning a few game-changing plays to the duration of the season. Weather, insufficient game-planning, and breathtakingly mesmerizing or shockingly underwhelming performances result in upsets at the season’s most crucial juncture.

It’s so infrequently about the better team, but instead the superior squad on a given day.

New England against Denver. Tom Brady versus Peyton Manning. Danny Amendola opposed by Wes Welker.

Discussions exhausted a thousand times over will be rehashed once more. Come Sunday night, when the Seahawks are getting ready to host the Niners, this round of questions will have ended. Only answers will remain, accompanied by a trip to the Meadowlands.

To think, the reward for winning something is a trip to New Jersey.

Throughout the week, we’ll look ahead to the Patriots-Broncos showdown with some of the big questions surrounding the matchup. First…

Is this the last meaningful showdown between two of the best quarterbacks of all time?

In all likelihood, this is the final chapter of any significance.

It’s impossible to know this is the end for sure, of course, but Brady and Manning are both on the wrong side of 35 and the AFC is bound to get stronger as the two continue to get older. The Patriots’ veteran overcame devastating obstacles to get his underdog team to this point, and the Broncos’ record-setter will only be a medical miracle for so long.

Should the future Hall of Famers meet again one day, odds are it won’t be to decide who plays in the Super Bowl. They’ve only gone head-to-head three times in the postseason, the last coming seven long years ago. A far cry from a trio of memorable battles in the span of just four years between 2003 and 2006, when it appeared this would be a near-annual occurrence.

Brady bested Manning’s former Colts in two of those meetings, and the elite signal-callers split a pair of AFC championship bouts. The home crowd has always left satisfied.

The Pats QB has claimed 10 of the 14 matches to date, most recently a franchise-best comeback from down 24 at halftime to win 34-31 in overtime in Week 12. To call that win impressive wouldn’t show it the proper respect, but its importance doesn’t hold a candle to what lies ahead.

This next game may be the one to shape their legacies in regard to one another, and perhaps finally end the talk over who is supreme. You’d think three championships compared to one, five trips to the final game as opposed to two, an 18-7 playoff record versus a 10-11 mark – or any number of other gaudy playoff facts – would have done that, but regular season statistics (and that doesn't mean wins and losses) dictate a different story. They keep an otherwise futile topic trendy.

As my colleague Chad Finn appropriately wrote, Manning has far more to lose this weekend than his 2013 campaign. Another Brady win would cement the conversation of superiority in his favor. But another Manning loss in a game he and his teammates were supposed to win? Even the most bizarre of in-game circumstances would still leave many viewing it as a Mile High plummet. At best, a Manning win would keep the dialogue going.

The 36-year-old Brady, severely limited in his pass-catching options for the first time in a half-dozen years, has had his most challenging and maybe most rewarding season since entering his 30s. He was the hero on a handful of occasions, sure, but other days called for his running backs or the defense to decide the outcome.

Manning, at 37, has an embarrassment of offensive riches – Wes Welker among them – and finished with his best year and arguably the top single-season performance for any man to ever play the position.

In a generation of lists, rankings, and what-have-you-done-for-me-lately historical analysis, this week will be filled with biographical game-by-game reflections of the Brady-Manning era. That parade is well underway.

For a moment, though, consider only this:

Brady’s first career NFL start came on Sept. 30, 2001, a 44-13 whooping of the Colts in a game in which Manning was intercepted three times. If an offseason neck exam doesn’t go well, Jan. 19, 2014 could mark Manning’s final contest. Perfect bookends to an otherwise unenviable situation.

Even if the elder, product-hawking Manning does return – and hopefully he will – we won’t see this again. The regular season, maybe, but not a Hat and T-Shirt Game. You can often depend on the best teams surviving a series in other sports, but that’s not how it works on the gridiron. Every game is a Game 7 and occasionally those ankle-biting underdogs prevail.

Pats fans hope that will ring true again. In the process, one of the greatest rivalries of a generation will also inevitably become a thing of the past. From the Brady-Manning Bowl to the Super Bowl, one final time. Enjoy what’s left and savor every snap. We’ll miss it when it’s gone.

Follow me on Twitter at @AdamMKaufman