Tim Tebow is doing what decades of conventional NFL wisdom said couldn’t be done. He’s winning game after game playing the most important position on the field less like a quarterback than an irresistible force of nature.

Seven times in their last eight games with Tebow in charge, the Broncos have somehow won when they shouldn’t have – six times coming back in the second half, five times in the fourth quarter and three of those in overtime.

Along the way, he’s befuddled critics, delighted his growing flock of fans and flummoxed opposing coaches, not to mention his own on occasion. He’s dazzled analysts and left it to teammates to explain the chain-reaction of events – freak turnovers by opponents, sparkling catches by young receivers, Tebow’s own runs through defenders – that have made the closing minutes of Denver games must-see TV. The latest one might have been the most improbable.

“If you believe,” he said after the Chicago win, “then unbelievable things can sometimes be possible.”

Mixing his football and his faith drew attention to Tebow long before he arrived in the NFL.

“His great strength,” said Chap Clark, a professor at Fuller Theological Seminary in Pasadena, Calif., “is that even people who don’t agree with his faith at all play their best around him.”

Tebow was no threat at all during his rookie season last season and for the first few games of this one.

But with the Broncos skidding at 1-4 with front-line quarterback Kyle Orton, first-year Denver coach John Fox grudgingly called on Tebow in the second half of an October game against the Chargers. Since then, it’s been an almost-unhindered ride up the elevator to the top of the AFC West and an even more unlikely playoff spot.

How Tebow does what he does is still something of a mystery, still so tough to quantify that his fiercest supporters call it divine intervention and everyone else, his coach included, still struggles to explain.

Right after the win over Chicago, Fox called it simply, “competitive greatness. He wants the ball in clutch time.”

A day later, Fox talked about how defenses often go into “prevent” mode late in games – “you know, they’re daring us to pass.” That’s what conventional wisdom suggests teams do against a quarterback who consistently ranks near the bottom of the league by most passing measures. And that’s what makes “Tebow Time” even more confounding.

In the 8 1/2 games he’s played as a starter, Tebow has taken the Broncos on scoring drives on just 12 of 76 offensive possessions through the first three quarters. On the opening drives of fourth quarters, the number is just 1 of 9. But for the remainder of the fourth quarter and into overtime, he’s choreographed the Broncos to touchdowns or field goals an incredible 16 of 28 times. Over that span, the defense has managed 10 takeaways, but half, notably, came in the final period or in overtime.

Around the league, opposing coaches scan scoreboards for late Broncos scores and their players rush back through the tunnel to catch the final few moments. A week ago, in case anyone missed the final score, 49ers lineman Mike Iupati walked through the San Francisco locker room hollering, “Tim Tebow, 6-1, baby!” And now he’s 7-1 in the pass-happy NFL, the best story the league has going.

When he got his first real shot at the job, watching Tebow play was something you did while peeking through the spaces between the fingers covering your eyes. It’s still the best way to watch the first three quarters. But after that, well, don’t dare take your eyes off him.