Things level off. This isn't news, but it deserves reiteration. Regression to the mean is a real thing in the long run, but it tends to be real in the short run as well. Remember that with fantasy defenses.
Through six games a year ago, Chicago had the league's best defense, averaging 18.4 points per game, 3.7 standard deviations above the average defense, while Jacksonville had the worst, 1.9 SDs below. By the end of the year, Chicago's defense was still at the top, but it was no longer a mathematical oddity, with its 13.25 points per game only 2.3 SDs above. Jacksonville had actually passed two units, and the worst, Oakland's, was only 1.6 SDs below the average.
That brings us to this year. Through six weeks, Kansas City's stout defense/special teams is averaging a full 19 points a game, solidly 3.3 SDs above average, with the Giants' abysmal unit sitting just below zero points a game and 2 SDs below the mean. The units are performing at historic paces (good or bad, you pick). But it won't hold. Maybe the Chiefs finish with the league's best defense. Maybe the Giants finish with the worst. But common sense, odds, and just plain math should tell everyone that their units will be closer to average by season's end.
How can that help in fantasy? A year ago, there was some talk about the trade value of the Bears' defense. They were outscoring the rest of the defensive units by so much, owning them was like having a weekly fantasy head start. So maybe you trade that head start as part of a package to get a stud at a more conventionally important position. Or maybe you can trade from excess in order to get that head start. Either way, we were discussing the trade value of a piece that normally doesn't get discussed in that context.
But, as I said above, the Chicago unit didn't keep that pace up. It was good. It wasn't record-setting good. If you traded it away when the discussions you were going on, odds are you were happier than the alternative. Similarly, this Kansas City unit is ridiculous right now. With an almost-40-point lead on the No. 2 defense, there's a good chance it ends the year at the top. But if trade offers start including defenses, and you can deal the Chiefs' unit, there is no greater sell-high candidate in all of fantasy.
That out of the way, let's take a look at some notable fantasy defenses for Week 7, with my ranking for the unit in parentheses:
Kansas City Chiefs (No. 1) - I stand by everything I wrote above. The Chiefs' D/ST is a great sell-high candidate. And, while Houston (or, more specifically, Matt Schaub) is certainly better than recent performance, the team as a whole has given up a pick-six in five consecutive weeks. Kansas City leads the NFL in turnover margin, while Houston is worst in the AFC, and second worst in all of football. Kansas City might fall off, but man if it's hard to imagine it happens this week.
Carolina Panthers (No. 6) - If the season started in Week 3, the Carolina defense would be averaging more than 14 points a game, which would be second in the league. Yeah, the games since have been against the Giants, Cardinals, and Vikings, so they haven't exactly faced a murderer's row, but they face the Rams and Buccaneers in Weeks 7 and 8. Defenses facing St. Louis have scored 0 and minus-1 points the past two weeks, but those defenses were Jacksonville and giving-up-a-million-defensive-scores Houston; before that, defenses worked St. Louis over pretty well. Have faith in the Carolina unit.
Cleveland Browns (No. 8) - The Browns' defense has scored double digits three times; they've scored at least seven every game except Sunday. It's strong against the run and, with Joe Haden matching up against opponents' top receiver, can shut down top-heavy passing games. Well, this week they face the Packers, who will be without Randall Cobb and could have a hobbled James Jones. Normally you wouldn't call the Packers' pass game "top heavy," but Jordy Nelson might be the guy Sunday, and he would draw Haden. Eddie Lacy and the running game will have their work cut out for them, and yards might be hard to come by.
Chicago Bears (No. 11) - For years, the Bears have been a defense-first team who just needed an offense that didn't screw it up. It's how Rex Grossman became a Super Bowl quarterback; it's why I'm writing this while wearing a Kyle Orton jersey (Oh, Kyle, we should be friends). This year, though, it has flipped, with a strong Bears offense (a good running back, decent tight end, and two usable receivers? Whoa, Chi-town) bolstering a defense that can't stop the run to save its life and doesn't do much against the pass besides forcing turnovers. The turnover potential keeps their value relatively high, but this is no longer an upper-tier unit.
Minnesota Vikings (No. 26), New York Giants (No. 27) - Some day, the NFL is going to figure out how to make Monday Night Football a flex matchup too, with the ability to slide another game in, because this is just sad. Anyone ranking all 15 games this week based on watchability wouldn't have Minnesota-New York higher than, what, 14th? Heck, it might be last. Anyway, defenses score really well against both Minnesota and New York, but these two teams have two of the worst defenses in the league. If I had to guess, I would actually say that whichever team wins this game does so behind its defense, and that defense will have season-best production, but (a) I don't feel that super-strongly, and (b) I have no idea which team it will be. If you feel like you have an idea who will win, maybe that defense is usable in a super-deep league.
Here are the overall rankings for Week 7:
|1||Kansas City Chiefs||Houston|
|2||New England Patriots||at NY Jets|
|3||Seattle Seahawks||at Arizona|
|4||San Francisco 49ers||at Tennessee|
|6||Carolina Panthers||St. Louis|
|7||Tennessee Titans||San Francisco|
|8||Cleveland Browns||at Green Bay|
|10||St. Louis Rams||at Carolina|
|11||Chicago Bears||at Washington|
|12||Cincinnati Bengals||at Detroit|
|13||Baltimore Ravens||at Pittsburgh|
|14||Tampa Bay Buccaneers||at Atlanta|
|15||Dallas Cowboys||at Philadelphia|
|16||Denver Broncos||at Indianapolis|
|17||San Diego Chargers||at Jacksonville|
|18||Green Bay Packers||Cleveland|
|21||Buffalo Bills||at Miami|
|22||New York Jets||New England|
|23||Houston Texans||at Kansas City|
|25||Atlanta Falcons||Tampa Bay|
|26||Minnesota Vikings||at NY Giants|
|27||New York Giants||Minnesota|
|29||Jacksonville Jaguars||San Diego|