Final Word: AFC South

Five nuggets of knowledge about Week 10:

Rare matchup: The 7-1 Texans pay a visit to Soldier Field for a date with the 7-1 Bears on Sunday night. According to the Elias Sports Bureau, it’s just the fifth time since the merger that two teams with one or no losses are meeting in Week 10 or later. The only other such matchup that happened within the past 20 years was a 2007 clash between the Cowboys and Packers. Good news for Bears fans: The home team has won each of the four previous such meetings.

Tough coverage: While he may get help, Johnathan Joseph should cover the Bears' most dangerous receiver, Brandon Marshall. Marshall accounts for 37.9 percent of the Bears’ targets this season -- the league high by 7.6 percent -- and 58.3 percent of the Bears’ receiving touchdowns. In 2011 and 2012, Marshall’s quarterbacks have thrown to him 37 times in the end zone. He’s faring far better catching those balls with Jay Cutler throwing them -- snaring five of 12 chances. Joseph had a couple of bad games when he was dealing with a groin injury, but he seems to be back to form. Houston defensive coordinator Wade Phillips talked about how Marshall is the only guy the Bears throw to. Houston’s pass defense will certainly be centered on him.

Finding his footing: After struggling in four of his first five games, Titans running back Chris Johnson has found his groove. Over the past four games, Johnson has averaged 131.5 rush yards per game. His 7.1 yards per carry average since Week 6 ranks second in the NFL behind Adrian Peterson among players with at least 30 carries. Tampa Bay’s Doug Martin is third at 6.6. Watch how Johnson’s offensive linemen try to sustain their initial blocks while allowing either fullback Quinn Johnson or tight end Craig Stevens to lead Johnson and make the key initial block at the second level. That approach has been making a big difference.

Third-down D: Houston and Chicago have topflight third-down defenses, which have had a direct impact on how quarterbacks fare against them. Houston has allowed the lowest QBR in the league (17.4), and Chicago has allowed the second lowest (20.6). The third lowest is the Eagles, and quarterbacks do far better against them with a 38.3 QBR. The Texans have the lowest conversion rate allowed (26.5 percent) on third down, with the Bears ranking third (33.0 percent). If some of this holds true in this matchup, the more poised quarterback should have the better chance of leading his team to the win.

Also: Matt Schaub and Jay Cutler have each won 11 of their past 12 starts dating back to Week 7 of 2011. That is tied for the best record by any starting quarterback in the NFL over that span. ... Schaub has yet to throw an interception on a play-action pass this season. ... The Dolphins have been terrible against the AFC South over the past seven seasons. Miami has lost three straight and 11 of its past 13 against the division. The Dolphins' last win in such a matchup, however, was over the Titans -- in Week 10 of 2010 season. ... Houston has yet to allow a rushing touchdown. ... The Colts beat the Jaguars 27-10 in Jacksonville on Thursday night. Indianapolis plays Week 11 at New England, while the Jaguars head to Houston.