Tim Tebow's winning success in five games has been the wild card of the crazy 2011 season.
Things get only crazier in Week 12. With a 4-1 record as a starter this year, Tebow mathematically has the Broncos in the playoff race. Imagine that. But two playoff contenders enter the weekend not knowing what to expect.
The Bears head to Oakland with Caleb Hanie as their starter in place of Jay Cutler, who had thumb surgery Wednesday. The Texans travel to Jacksonville with a different Matt running their offense as Matt Leinart replaces Matt Schaub as Houston's starter.
Since the start of the season, 13 quarterbacks have come off the bench to replace opening-day starters and, except for Tebow, Oakland's Carson Palmer and Matt Moore of the Dolphins, it has been a struggle for them. Those quarterbacks have a combined 16-30 record. If you throw in Kerry Collins' 0-3 record filling in for Peyton Manning, replacement quarterbacks are winning only a third of their starts.
Tebow went against the odds with his running style of offense, but what can the Texans and Bears expect from Leinart and Hanie? If both go 2-4 in their last six games, matching that 33 percent replacement quarterback winning percentage, the Texans and Bears might not make the playoffs. It still seems the Bears will need at least 10 wins to get a wild card. The Texans have to make sure they get to 10-6 or the Titans could jump back in the AFC South race.
What's even more interesting is how Hanie and Leinart affect other playoff contenders. The Raiders have to feel better defending against Hanie than Cutler. Following Leinart's first start, the Texans face the Falcons and Bengals, who might have a better chance of beating the Texans without Schaub.
Here are the 10 things to watch in Week 12.
1. Changing the Matt: Of the two new starting quarterbacks this weekend, Leinart has the easier challenge. He faces rookie quarterback Blaine Gabbert and the Jacksonville Jaguars, who don't figure to put up many points. That should give Leinart four quarters to get comfortable in his new role running the offense. The Jags are averaging 12.5 points a game. Gabbert is completing only 48.9 percent of his passes, and other than Mike Thomas and Marcedes Lewis, he doesn't have many pass-catching threats. Plus, Texans defensive coordinator Wade Phillips should come up with blitz packages that will confuse Gabbert and keep the score low. Phillips has shaved 10.1 points off last year's defense that was surrendering 26.7 points a game. Leinart will be expected to hand the ball off with Arian Foster and Ben Tate and run a few bootleg throws to move the offense. The Jaguars have a solid defense, so this figures to be a low-scoring game.
2. Can Hanie save the season? Looking back to last year, the Bears made a mistake not making Caleb Hanie their backup quarterback. Worried about his inexperience, the Bears felt more comfortable going with 39-year-old Todd Collins. Unfortunately, Collins was awful. Despite the Bears' 23-6 victory over Carolina, Collins completed 6 of 16 passes for 32 yards, four interceptions and had a 6.2 quarterback rating in a disastrous performance. At least Hanie completed 13 of 20 against the Packers filling in for Cutler during the NFC Championship Game. Cutler going against Carson Palmer would have been interesting, but Hanie versus Palmer will be a problem for the Bears. The good news for Hanie is the Raiders' defense stays reasonably conventional. According to ESPN Stats & Information, the Raiders rank seventh in the league for rushing four or fewer defenders. The bad news is the Raiders' defensive front four is good enough to overpower the Bears' banged-up offensive line. Hanie figures to use screen passes to Matt Forte and quick throws to the outside to slow down the Raiders' defensive line. The Raiders figure to stack the line to stop Forte and force Hanie to go to the air.
3. Tebow time in San Diego: How bad are things in San Diego? Tim Tebow comes to town with a better record than the Chargers and Philip Rivers. Lots of jobs are on the line in this game. It's pretty evident Chargers coach Norv Turner has to turn around his 4-6 season to keep his job. He has two years remaining on his contract at $3 million per year, but the team looks like an old car trying to get to the repair shop. Pass-catchers aren't getting downfield or aren't getting open. That hasn't stopped Rivers from forcing throws, which has resulted in 17 interceptions. With all the injuries on defense, the question is whether the Chargers can put up a 60-minute effort to stop Tebow. The Dolphins and Jets showed how to play Tebow for 55 minutes. You clog the middle of the field to stop the inside runs, have a spy around to make sure Tebow doesn't break containment with a run, and basically play the run. Both teams failed when they tried to play the pass instead of the run in Tebow's last-minute scoring drives. Tebow is also playing for his job. Even though he's at the threshold of guaranteeing his salary for next year with his playing time, Tebow learned this week from Broncos president John Elway that Tebow hasn't helped Elway figure out if the Broncos have their quarterback of the future.
5. Which offense is on the bigger decline? In losing their last three games, the Bills have scored only 26 points and Ryan Fitzpatrick has completed only 54.5 percent of his passes for 182.0 yards per game. He's thrown seven interceptions and two touchdown passes during that stretch. The Jets started the Bills' three-game skid by figuring out how Buffalo spreads the field to run the ball and work the short passing game. Since then, the Bills' offense has been solved. To make matters worse, the Bills won't have running back Fred Jackson because of a broken leg that has ended his season. Last Sunday, they lost wide receiver Donald Jones for the season with an ankle injury. But what's up the Jets' offense? In their past two games, the Jets have scored only 29 points and Mark Sanchez has looked awful. Things were so bad for Sanchez that Rex Ryan gave backup Mark Brunell a few snaps with the first team. Sanchez, by the way, wasn't pleased with that decision. Sanchez isn't in danger of losing his starting job, but the Jets are in danger of falling out of the playoff race if they lose this game. The lack of a running game, shaky offensive line blocking and receivers not getting separation from defenders have caused Sanchez to make more mistakes and bad decisions.
6. Jumping on the Ryan Express: With a 6-4 record and the Bears wondering how their season will be minus Jay Cutler, Matt Ryan and the Falcons are poised to make a wild-card run. They may even see if they can catch the Saints for the NFC South lead. Last Sunday's victory over the Titans was huge because Ryan connected on seven of 14 throws to Roddy White. White didn't have a great first half of the season because of a twofold problem. First, Ryan and White need an entire offseason together to work out their routes. Second, the addition of rookie Julio Jones changed the dynamics of the passing offense. Jones' downfield speed opened up the middle of the field for tight end Tony Gonzalez, so he's getting more downfield catches and some of them are in the area where White used to catch passes. Jones might be another week away from returning because of his hamstring injury, but once he does, this offense might really start clicking. The Falcons shouldn't have much trouble with the Vikings because Minnesota comes in with rookie quarterback Christian Ponder and a defense that is running out of gas.
8. Sunday night in Kansas City: NBC put in for the Chiefs-Steelers game because it thought a Matt Cassel-Ben Roethlisberger matchup of two 2010 playoff teams would be interesting. Whoops. Cassel's done for the season, and Dick LeBeau's blitzing defense gets to see how it can disrupt lefty backup Tyler Palko, the former Pitt quarterback who figures to get one final start before waiver claim Kyle Orton takes over in Week 13. And don't read much into Roethlisberger's broken thumb. It's a small break and it won't prevent him from playing. This one could be ugly.
9. Dalton's wild-card run: In seven-point losses to both the Steelers and Ravens, Bengals quarterback Andy Dalton gained a lot of respect for being able to keep his team in games against the AFC North's two best teams. Though he has a tough challenge next week in a game against the Pittsburgh Steelers, Dalton needs to get Sunday's home victory against the Cleveland Browns. Dalton has already surpassed Browns quarterback Colt McCoy as the division's best young quarterback. Dalton took the edge with a 27-17 victory over the Browns in the opener. Aside from two remaining games against the Steelers and Ravens, the Bengals have four winnable games left -- Cleveland, Houston without Matt Schaub, St. Louis and Arizona. If they can get to 10-6, they might grab the last wild-card spot and be the third team from the AFC North to make the playoffs.
10. Bottom-feeders: If they can beat the visiting Washington Redskins, all of a sudden, the Seahawks have a chance to go on a three-game winning streak. That might spoil their chances of getting a top young quarterback next season, but Pete Carroll is trying to get his team to .500. The Seahawks are 4-6. Panthers quarterback Cam Newton should get his third victory of the season as long as the Panthers' defense doesn't betray him in Sunday's game in Indianapolis. Even with the return of Sam Bradford, the 2-8 Rams have looked horrible. They go against an equally disappointing Arizona Cardinals team in a game that lacks buzz.
John Clayton, a recipient of the Pro Football Hall of Fame's McCann Award for distinguished reporting, is a senior writer for ESPN.com.