The Broncos keep winning despite Peyton Manning's continued decline

Denver remains undefeated thanks to an excellent defense and despite quarterback Peyton Manning's continual decline.

You can see the cracks in his armor as clear as the lines on his face, as sure as the deep needles he regularly used to thread and as plain as his folksy press conference quips. Peyton Manning is old, and that world-taming skill of his youth isn’t coming back. He’s out there, still running naked bootlegs, still calling “Omaha,” but now he’s wheezing out slant throws and tossing pick-sixes. What we’re seeing is not the Manning of old. It’s the Old Manning.

The 1998 No. 1 draft pick out of Tennessee is now 39 years old — long past the expiration date of all but the rarest of NFL quarterbacks. Only 18 have played into their 40s, and with each passing game, it’s become increasingly difficult to imagine Manning becoming the 19th. For as jarring as his descent into replacement-level QB play has been to watch, fans have had plenty of time to prepare.

When the Denver Broncos won Peyton-palooza back in 2012, there was a mix of hope and trepidation. Sure, the city by the Rockies provided a soft landing for the future Hall of Famer, but we wondered: Would he be the same after the four neck surgeries that led to his silent swan song in Indianapolis?

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And then, as he’d done so many times before, even against the odds this time, Manning wowed the world with brilliance and precision. He’d crafted a legendary second act, stringing together arguably the two finest seasons ever engineered by a quarterback, in 2012 and 2013.

The numbers remain astonishing. A 68.5% completion rate. More than 10,000 yards and 92 touchdowns. Two straight seasons leading the league in net yards per pass attempt. It was an enthralling run, punctuated by his third Super Bowl appearance.

But last year, nestled deep within another 12–4 season — the 11th time in Manning’s career he’d won at least that many games — you could begin to see the signs of age and rust. The zip on his fastball began to wane. The blistering dominance relented. There was a stomach bug, and a thigh injury and whatever else. His completion percentage dipped below 64 for his final seven games, and he tossed just 10 touchdowns against eight interceptions. By the end of 2014, Manning was a weary, battered warrior, gritting through a grueling NFL season the way most in their late-30s eventually must. The smarts and deft misdirection were still there, but a chill now had seeped into Manning's hot game.

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When legends begin to lose their luster, we give them the benefit of the doubt. Many reasoned with what we were seeing unfold, and figured a full off-=season of rest and healing could give Manning that spark he needed to return to  something close to his customary excellence.

It’s now 2015. The results, through six games, are in. And so far, Manning is having the worst stretch of his NFL career since his rookie season 17 years ago.

He’s completing 61.6% of his passes. He’s thrown 10 picks against just seven scores and is tossing touchdowns at the lowest rate of his career. His rate stats are dismal, scraping new career lows in adjusted net yards per attempt, yards per completion, and dangerously close to it in quarterback rating. We can see he’s checking down more often, and getting sacked and pressured at an alarming rate. Where once we watched a surgeon, we’re now watching an aging blacksmith, hoping to craft one final masterpiece on muscle memory and guile.

Some of the blame for Manning’s queasy play must be shared with his offensive line, which has demonstrated little interest in pass-blocking or in clearing holes for C.J. Anderson or Ronnie Hillman . If you watched the Broncos only on the offensive side of the ball, and were told “this team is undefeated,” you’d question your sanity. Manning’s name and the team’s sterling record are masking myriad shortcomings.

Indeed, the Denver Broncos are 6–0 (aided by playing a slate of teams with a combined record of 10–24, including arguably the three most under-performing teams so far in Baltimore, Kansas City and Detroit). They are winning not thanks to offensive pyrotechnics, but with a vengeful defense led by twin terrors Von Miller and DeMarcus Ware, and with cornerback Aqib Talib finding the end zone like a vintage Ed Reed.

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Thanks to that defense, there’s almost certainly going to be another January of Peyton Manning football, but this one may look different. If something doesn’t change significantly between now and then, playoff doubts won’t just rest on Manning’s squirrely postseason record, but on his actual ability to play the position competently — a thought that seemed unfathomable just a year ago.

When you have witnessed transcendent excellence, it’s always the hardest to watch it fade away — even though it will, eventually. Autumn always turns to winter. Even the Rocky Mountains themselves will one day erode into gentle hills. All prominence, all brilliance, all greatness eventually withers, whether we’re ready for it to leave us or not. Manning and Denver are giving this one more try before some difficult decisions will have to be made. You hope for their sake that the Broncos are preparing for the end — and, for his sake, that Peyton Manning is, too.