NFL power rankings: Bears, Steelers, Packers bump up; Ravens, Rams drop for Week 7

Key points

• Week 7 NFL power rankings place the Kansas City Chiefs at the top after a 5-0 start, with Kenneth Walker III producing huge rushing numbers. The San Francisco 49ers and Minnesota Vikings also remain unbeaten, with the Vikings' defence credited for holding opponents to a league-best 22 percent on third downs.
• Buffalo's Josh Allen is putting together a career-best season that strengthens his MVP case.
• The Chicago Bears, Pittsburgh Steelers and Green Bay Packers have climbed, while the Los Angeles Rams and Baltimore Ravens have slipped.