ENGLEWOOD, Colo. -- If folks can get past the who’s-the-best argument or the which-career-would-you-rather-have discussions, there is so much to appreciate when Peyton Manning of the Denver Broncos and Tom Brady of the New England Patriots face each other on a football field.

They have each won piles of game, thrown buckets of touchdowns, baffled defensive coordinators, punished mistakes in coverage and been accurate enough to construct touchdowns even when defenses don’t make a mistake.

"That’s what the best of the best do," said Champ Bailey, who announced his retirement this week after a 15-year career that saw him named to 12 Pro Bowls at cornerback. "Those two, they know what you’re doing, they punish your mistakes, every time, they don’t miss it. Some guys you make a mistake and they don’t find it, [Manning and Brady] find it every time. And then even if you do everything right, they still can punish you. And they’re doing it now, maybe even better than they’ve ever done it. They might just keep going."

Manning is already on uncharted ground, having thrown a single-season record 55 touchdowns at age 37 and is on a staggering 50-touchdown pace at age 38.

Brady, who turned 37 this past August and is coming off a five-touchdown effort last Sunday -- his 17th game with at least four touchdowns without an interception, has said he would like to play into his 40s.

That means, like so much of what they have done to this point, what they do in the months and years to come will separate them from most who have ever played the position.

Consider there are 10 modern-era quarterbacks in the Pro Football Hall of Fame who did not play beyond their 36th birthday. That list includes Troy Aikman, Terry Bradshaw, Dan Fouts, Jim Kelly, Bob Griese and Joe Namath.

Of the 13 other modern-era quarterbacks enshrined, only John Elway, Manning’s current boss with the Broncos, Fran Tarkenton and Warren Moon threw more than 20 touchdown passes in a season at 38 or older.

Moon, who didn’t reach the NFL until he was 28, threw 33 touchdown passes when he was 39 and 25 touchdown passes when he was 41 -- in the 1997 season.

So, as folks in football celebrate what the Brady-Manning rivalry has been through the years, it’s worth a pause to consider what it can still be.