ENGLEWOOD, Colo. -- Tim Tebow didn't win the Denver Broncos' starting quarterback job as much as Kyle Orton lost it.

Either way, Tebow has ditched his cap and clipboard and is now the starring attraction in Denver.

Coach John Fox made the switch official Tuesday, announcing Tebow will start against the Miami Dolphins when the Broncos return from their bye week.

He supplants Orton, who has struggled ever since winning the job with a spectacular training camp.

"Well, I think 1-4 has a lot to do with it," Fox said. "We haven't gotten it done as a football team. It's not one guy. It's not all Kyle Orton's fault. But we do have to make adjustments, we have to change and we have to do something to win football games."

Orton didn't carry over his sensational summer into the regular season, turning the ball over nine times and losing the organization's confidence and a string of winnable games as the Broncos stumbled to another bad start.

Fox had seen enough by halftime Sunday when he benched Orton and sent in Tebow. After a slow start, the former Florida star sparked a listless offense to within a last-gasp pass of coming back against San Diego.

As the Broncos trudged off the field, the stadium shook with a thunderous roar of "Tebow! Tebow! Tebow!"

Fox appreciates their passion but said the fans, who have been calling for Tebow ever louder by the week, had nothing to do with this move.

"It's not so much fan outcry as we're in a result-oriented business, and we're 1-4," Fox said. "It's not one guy. We'll see if this helps."

Tebow had his troubles -- rust, three fumbled snaps and six misfires in 10 pass attempts -- but he ran for a touchdown and threw for another while energizing the Broncos and fans frustrated by a franchise mired in mediocrity since its last winning season in 2005.

After thinking things over for a day and watching the game film, Fox decided to go all-in with Tebow.

It's time to see what he has in the popular and polarizing 24-year-old lefty, one of the most accomplished players in the history of college football but one whose skill set doesn't fit the mold of a prototypical pro passer.