Is the performance of a team defense less predictable than the performance of other fantasy football positions?

Because of the way that most standard leagues operate, statistically arbitrary defensive plays tend to be heavily weighted. Fumble recoveries, interceptions and and defensive touchdowns can be gamebreakers, or they can be irrelevant, but they don't usually have nearly as much to do with the defense as they do with the player committing the turnover. While fantasy baseball considers wins, fantasy football usually doesn't. I've always felt that simple wins should probably be a metric. They should be weighted depending on the points allowed, but they should definitely be a consideration. Sacks aren't super constant, but compared to turnovers, they might as well be written in stone. The leagues that have the most consistent scoring defenses are the ones in which special teams yardage is figured into the scoring. Not everyone does this, but because punt and kick returners are basically offensive players, their statistics don't change as much from year to year. It should be noted that returners don't generally have long peaks (there are exceptions that prove this rule.) Add weighted wins to a defensive scoring system and you may get to where you need to go. If the fantasy point differential between a winning defense and a losing defense is large enough, you'll start to find that they'll win leagues. Most of this information is anecdotal or synthesized from PFP, so for what it's worth, you could look there. I've also not yet been in a league that's done this, so it's theoretical.

Get on over to http://www.fantasyfootballcafe.com/forums/ and discuss it there. There is a fellow called "comm1680" on those forums who uses an elaborate mathematical formula to http://www.fantasyfootballcafe.com/forums/viewtopic.php?t=419374. He takes a lot of things into account, and his rankings are far superior to chance. He likes to talk about how he does it, too.

I don't think there's any way to answer this question without knowing how your league is structured. Is it a keeper league? If so, how many players do you keep? What's your scoring system, especially for the defenses? Without knowing this information, there's no way to give an informed answer. The league I've run for 20 years is a keeper league. There are 16 teams with 15 players each. Teams are allowed to keep 9 players before the draft. Most teams do keep a defense before the draft, but defenses, kickers, and tight ends basically have the same weight. That is, owners will keep QB, RB, or WR before any of the others. Here's http://football10.myfantasyleague.com/2008/options?L=13417&O=09. For defenses, it works like this:Fumble Recoveries (from Opponent) 2 points eachInterceptions Caught 2 points eachSacked a QB 1 point eachSafeties 2 points each Total Points Allowed 0-3 6 Total Points Allowed 4-8 5 Total Points Allowed 9-10 4 Total Points Allowed 11-13 3Total Points Allowed 14-16 2Total Points Allowed 17-19 1Number of Defensive & Special Teams TDs 6 points eachWe also used to have points based on yardage, but that was overturned because most owners thought it was too arbitrary. Finally, defensive teams don't add their points to our offensive totals -- they subtract from the opponent's offensive totals. For a long time, we were the only league I knew that did this, but I think it's becoming more common now. During any given year, there do seem to be a few defenses that consistently score well. There are also defenses that don't. And from year-to-year, there's some (not a lot) of consistency. Chicago has been very good for the past few years, at least in our league. HOWEVER, there's no real long-term consistency, which is why defenses in our league don't get favorable treatment like QB/RB/WR. You know that Tom Brady is going to score you 8-12 points every week for his entire career. (Until he gets knocked out during the first game of this season — argh!). You don't know that about the top defenses. Long answer, I know, but I used to be really into this stuff, and I've thought a lot about it. I've also run a lot of numbers. (Look around. It used to be easy to find data dumps you could import into Excel to run your own analysis on.) I'm not as into it anymore, but I still have opinions and impressions...

Defenses are harder to predict in my experience simply because, as mentioned, there's a lot of weight on arbitrary plays. You could have a defense with a couple of outstanding CBs that pick off a pass a game, but they may never return an oski for a TD in a season. Meanwhile, your opponent's defense just happens to catch a lucky break and returns a fumble for a TD, so now they've outscored you. In the NFL, there are maybe five very good to excellent defenses, five poor defenses, and 20 that just kinda depend on the day of the week, weather conditions, whether the defensive coordinator took his smart pills this morning, etc. WRs seem to be better choices for points... so long as they're #1/#2 targets. Even then, scoring TDs isn't a guarantee, and you're really thinking more about their consistency. In a 1 pt = 10 yrds league, a 1000 yd receiver should average over 6 pts/game before TDs. In reality, of course, they'll have 3-4 point weeks and 10 point (+ 100 yds receiving bonus if your league has that) weeks.