Power Rankings: How do you spell unbeaten? D-E-F-E-N-S-E

Updated Sept. 30

Take a look at the top three teams in the CBSSports.com Power Rankings. The New York Giants, Tennessee Titans and Buffalo Bills are all undefeated, the only three teams without a loss.

They also have something else in common, which is why they are where they are -- it's called defense.

As much as I hate to admit it, since I am a connoisseur of offense, defense is ruling the NFL early on.

As we raced to anoint the Dallas Cowboys as the team to beat, we lost vision of their so-so defense. Buried under their high-scoring, fun-to-watch offense is the Cowboys' 20th-ranked scoring defense, which is giving up 22.2 points per game.

The top three teams in the rankings are all in the top 10 in scoring defense. The Titans are tops in the league with an average of 11.3 points allowed, followed by the Giants, who are tied for second with Baltimore at 14.3. The Bills are sixth at 15.8.

Those three are also in the top 10 in sacks, with the Titans tied for second with the Steelers at 15, the Giants have 13 in three games to tie for fourth with the Jets and the Bills have 10 to tie for 10th with three other teams.

Getting after the quarterback is a must in this NFL. The three top teams in our rankings show just how important.

Poll Which unbeaten team has the best defense?   15%  Bills     27%  Giants     58%  Titans     Total Votes: 48576

The Cowboys fell from the top spot to No. 5 by losing to the Washington Redskins. Washington, which has won three consecutive games, is a big mover in these rankings, jumping from 12th to fourth.

They're not like the top three teams. They are 15th in scoring defense and have just six sacks to rank tied for 23rd with three other teams.

The Redskins are making their move behind young quarterback Jason Campbell. He has developed into a capable passing threat that gives them a chance every week.

I love watching the Cowboys' offense, but even I know a 20th-ranked defense isn't good enough. If that defense doesn't improve, their perch in the top five won't last long.

The Power Rankings though Week 4:

Power Rankings
Current		Team	Previous
	1	Patriots · Trends	11
	They get Tom Brady back. They have the deepest team in the league. Oh, and they have the best coach. Add it up, and it's no wonder they are Super favorites.
	2	Steelers · Trends	1
	The champions are loaded again and will be in the thick of it come playoff time. They didn't do much to improve their offensive line, though, which has to be a concern.
	3	Colts · Trends	7
	Peyton Manning is back healthy again, so they are a real contender again. The addition of Donald Brown to the running game will give it more explosiveness. The key will be the return to health of major defensive players.
	4	Cardinals · Trends	2
	They've done some nice things in the offseason, including adding corner Bryant McFadden and drafting Beanie Wells to carry the football. They will be a playoff team again and maybe they'll finish in Miami.
	5	Eagles · Trends	4
	They've had a wonderful offseason, adding key players like tackles Jason Peters and Stacey Andrews and loading up in the draft with speed and quickness. They will be tough to stop on offense.
	6	Giants · Trends	5
	They fortified the defense with some key free agents and added a speed receiver in Hakeem Nicks to the passing game. Tom Coughlin will have this team in the playoffs again.
	7	Titans · Trends	6
	They haven't done a lot, and losing Albert Haynesworth will hurt. The other thing is their division is tough. They also have to get more big plays from their passing game.
	8	Ravens · Trends	3
	Joe Flacco will be better in his second season as a starter and that defense will once again be among the best. They do have to take their passing game up a notch.
	9	Falcons · Trends	9
	It's all about the defense for the Falcons. Adding Tony Gonzalez makes the offense complete and the draft was loaded with defensive picks to help the other side. They aren't going away.
	10	Saints · Trends	19
	This is another team that has improved its defense in the past four months in terms of talent. Now new defensive coordinator Gregg Williams has to bring it all together.
	11	Chargers · Trends	10
	This is still a deep, talented team. If Philip Rivers continues to develop, the Chargers will easily be the class of the AFC West.
	12	Texans · Trends	17
	The Texans have a lot of important pieces in place. As long as Matt Schaub can stay healthy, they might be ready to make a real playoff push.
	13	Panthers · Trends	8
	They will be the same team: Run heavy and play tough defense. Is that enough? Jake Delhomme has to play better.
	14	Bears · Trends	18
	Getting Jay Cutler is the steal of the offseason. He makes them a real playoff threat. Yes, I do believe that.
	15	Cowboys · Trends	14
	They have talent, but something just seems to be off. I don't think they're as good as the Eagles or Giants in their own division, which is why they are down this low.
	16	Bengals · Trends	24
	Getting Palmer back makes them dangerous and the defense will be better around him. I like the Bengals as a sleeper team. I really do.
	17	Vikings · Trends	13
	Quarterback. It's all about the quarterback. Whether it's Sage Rosenfels or Tarvaris Jackson, that position has to be better. Words of advice: Stay away from that guy named Favre.
	18	Packers · Trends	23
	The move to a 3-4 under new coordinator Dom Capers will be one to watch closely. If that side of the ball plays better, Aaron Rodgers might get them to a playoff game.
	19	Bills · Trends	22
	Can Terrell Owens make them a playoff team? That might be stretching it, but they will be better on offense.
	20	Seahawks · Trends	28
	New coach Jim Mora takes over a veteran team that was hurt by injuries last season. They need to keep Matt Hasselbeck healthy. If they do, they will push the Cardinals.
	21	Jets · Trends	16
	How long does it take to get Mark Sanchez ready? If he's what they think he is, they will be better than expected. If not, it's a redshirt season and they will win six games.
	22	Buccaneers · Trends	15
	Who plays quarterback? Whoever it is has to be better than what they had last season. There are also some age concerns on defense. New coach Raheem Morris faces a challenging first season.
	23	Redskins · Trends	25
	They're the fourth team in a four-team division. That will make it tough to win eight games.
	24	Jaguars · Trends	26
	They've made some nice moves to fix the offensive line, and now it's time for the offense to do more. The defense also needs young players to step up, especially end Derrick Harvey.
	25	Broncos · Trends	20
	They're excited about Kyle Orton. I'm not. I think he's OK. They better hope the defense plays better than a year ago or it won't matter who quarterbacks the Broncos. I do like Knowshon Moreno.
	26	Dolphins · Trends	12
	They are the step-back team this season. But in 2010, look out. I think Chad Henne will take over at some time this season.
	27	49ers · Trends	21
	It's all quarterback with the 49ers. Can Shaun Hill or Alex Smith get the job done? If not, they'll stay down here all year long.
	28	Raiders · Trends	27
	It's all about JaMarcus Russell. If he plays an entire season to the level of expectations, the Raiders will be better. I think he can. But they have other issues.
	29	Chiefs · Trends	29
	They landed their quarterback in Matt Cassel and have added a few players to help, but new coach Todd Haley faces a big task in getting this offense to play like his Arizona unit did.
	30	Browns · Trends	30
	New coach Eric Mangini will build this team the way he wants it. But one has to wonder if that's a good thing considering his Jets history.
	31	Rams · Trends	31
	The Rams were a disaster last year. New coach Steve Spagnuolo has a lot of work to do. They're at least a year away.
	32	Lions · Trends	32
	They have their franchise quarterback to build around, and Jim Schwartz will do a good job, but there's a lot of work still to be done.