Nothing ignites a good NFL discussion quite like quarterbacks. And it makes sense: They're the most important ingredient in a championship recipe. All quarterbacks, of course, are at least partially a product of their situations,

The Kansas City Chiefs, the lone undefeated team in the NFL, stand alone atop the On SI Week 8 NFL Power Rankings. The Chiefs have been slammed by injuries and

The Steelers have a top-10 defense this season and the best special-teams unit so far. One concern is that they have played the ninth-easiest schedule to this point and have the eighth-hardest schedule going forward. Pittsburgh will need that offense to be better than below-average if they are to navigate a tough stretch of games.