He took over when they were already 1-4.
"Backed into the playoffs" is a something that happens all the time but was not made into a catch phrase until Tebow came along.
But it was true. The Broncos were 8-5 thanks to a strong defensive performance needing only one more win to clinch a playoff spot in the last 3 games on a schedule that included the Buffalo Bills... who they got rolled by, and the Kansas City Chiefs who had just fired their coach and had Kyle Orton of all people leading them. They didn't do it and got in only because the rest of the AFC West had some sort of an allergic reaction to the division title.
Tebow managed a whopping 3 points against the Chiefs in a must win game to beat Orton, but lost 7 to 3. That 3 points came on a muffed punt giving the Broncos the ball well within field goal range when Tebow ended that drive with yet another of his patented three and outs.
He took over when they were 1-4, but he also finished 1-4 when MOST of the league figured him out. Pittsburgh just did a horrid job covering Thomas seemingly thinking they didn't need to bother covering him. But the passing offense went down, overall offense went down. Scoring went down. Completion percentage went down. Third down conversion rates went down (believe it or not) as did trips to the red zone. Three and outs went way up to make the Broncos the league leader that year. About the only thing positive that was tangible on offense was the rushing yards being #1, but that was just good enough to have the offense around 25th overall.
So how could they take such a large step back on offense and start winning games? Easy, the defense did most of the heavy lifting and they got a schedule against more mediocre offenses. They were exposed when they met a real offense like that of the Patriots (TWICE) and once it was shown the defense can't hang with Tebow punting the ball back to Brady after every third play, Tebow himself became a rediculous non-factor.
Nice job moving the ball and completing comebacks against soft prevent defenses, as not every guy can do that, but it has somehow made believers in a lot of people that actually think it means Tebow is a lot better than he actually is. Fools gold!! Most NFL fans not viewing the world through Tebow colored lenses are sophisticated enough to recognize it, and this is why no team gave a serious thought to bringing him in to try to start for their team. Talking about him taking a team from 1-4 to 8-8 with a playoff win is a serious oversimplification of what actually happened and puts far too much credit on Tebow, who spent 90% of his playing time helping dig the hole the Broncos often found themselves in for most of the game with his ineptitude at QB.
True, the defense did no favors by not stopping Brady, but punting the ball back to brady after about 2 minutes and only 3 plays = not a good formula for beating the Patriots.
Maybe the Patriots can salvage something out of him, but I truly think that answer will have less to do with Tebow being a starting QB in this league.