It is exceedingly difficult to predict how defenses will fare over the course of the season. In 2016, half of the preseason top 12 fantasy defenses failed to finish top-12. Some of them didn't even come close. Others that were ranked highly barely stayed in the group.

There are very few defenses that I consider "set it and forget it" type defenses. Selecting what defense to start is more about opponent than the actual ability of the defense. I'm probably starting New England and Denver against just about anyone. But even they have some opponents that give me pause.

Here are a few defenses that may not be great in real life, but will be great in fantasy.

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Defensive Sleepers for Fantasy Football

Pittsburgh Steelers

I don't typically see the Steelers ranked very highly. They're a top-12 defense just about everywhere, but they should be consensus top-five. If I can't get the Patriots, then the Steelers are flat out the next defense that I want. The Steelers don't face a good offense until I guess Week 6 at Kansas City. They open with three of their first four on the road, which is less than ideal because you typically want defenses at home, but take a look at their opponents in those road games. They start out with DeShone Kizer, who is, for lack of a better word, terrible. In Week 3, they go to Chicago to take on Mike Glennon. They follow that up with a trip to Baltimore to face the wildly overrated, currently injured Joe Flacco. Mixed in are their two home games against Sam Bradford and Blake Bortles. Are you scared of any of these QBs?

The schedule toughens up a bit in the second half of the season, but so much will change by then. You need not worry about what defense you're going to use beyond, to be perfectly frank, week one. That's really all I care about when drafting a defense. Find a defense with a great week one matchup and figure it out from there. The Steelers are an ideal option because they are underrated as a whole by the fantasy community and they actually have a relatively favorable first six weeks.

Jacksonville Jaguars

Why aren't the Jaguars being treated as a top-five defense? They're certainly a top-five real life defense. Obviously Blake Bortles is a concern as his inability to do anything positive puts the defense in bad positions, but this defense can score you points. They have a favorable week one matchup against Tom Savage in Houston, which is enough to warrant rostering them. If you can stomach Week 2 against Marcus Mariota, which, although not easy, is in Jacksonville, you get the Ravens in Week 3 and the creme de la creme of 2017 matchups in Week 4: the Jets.

The Jaguars have a healthy Dante Fowler and signed AJ Bouye to pair with Jalen Ramsey for what is undoubtedly one of the best cornerback tandems in the league.  They are very startable in two of the first three weeks and will likely be the number one fantasy option in week four (as the team facing the Jets will be most weeks).

Los Angeles Chargers

This defense is ranked far too low everywhere I see. If you need a defense to stream early on, why not the Chargers? Is anything scary about their first four opponents: Trevor Siemian, Jay Cutler, Alex Smith, and Carson Wentz? After that, you can drop them for the game against the Raiders, pick them back up for the Broncos game, and then drop them for the game against Patriots. Then, three of their next four games are against Blake Bortles, Tyrod Taylor (or maybe Nate Peterman), and Deshone Kizer.

The Chargers have an elite shut down corner in Jason Verrett as well as a pass rushing phenom in Joey Bosa. Jatavis Brown is one of the most underrated and unheralded linebackers in the league. There is a lot of talent on this defense and I'm not sure many people realize it. In the right matchups, of which there are many, the Chargers will be very useful. You should be able to stream them all season with ease (or at least until people catch on).

Los Angeles Rams

This defense was supposed to be quite good last year. As we learned from "Hard Knocks" and "All or Nothing," Gregg Williams is one of the most incompetent defensive coordinators in the NFL. He has no idea what he's doing. All he does is scream obscenities and cliches. Gregg Williams is now gone. Replacing him is Sean McVay's handpicked defensive coordinator, Wade Phillips, one of the best defensive coordinators of all time. It would help if he had Aaron Donald, who is currently still holding out, but we're more concerned with the opponents here.

The Rams open with a home game against what could be the worst team in football - yes - worse than the Jets - the Indianapolis Colts. I firmly believe that if Andrew Luck missed the entire season, the Colts would win no more than two games. Luck is not going to play week one. Does anything about Scott Tolzien on the road excite you? Actually, the answer is yes. The prospect of starting the Rams defense against Scott Tolzien excites me and is something you should definitely consider. You probably don't want to use them week two against the Redskins, but they'll be useful once again in week three against the 49ers. Beyond that, the favorable matchups are few and far between, but for two of the first three weeks, the Rams will be a top-eight fantasy play.

Buffalo Bills

I do not think the Bills have a good defense and you don't want to own them for an extended period of time. But they are worth drafting for one simple reason: they open at home against the Jets Week 1. Any defense against the Jets is automatically a top five fantasy play (probably top one). Draft the Bills. Start them against the Jets. Then drop the Bills until the next time they play the Jets. It's that simple.

Too many times I see fantasy owners trying to find a defense for the season. That should not be your goal. Fantasy is a weekly game and you only need one defense - you can find one on a week to week basis. It is important to plan ahead and after you realize most of your late round picks aren't worth owning, you'll have the roster space available to stash a defense a week in advance to ensure you always get the one you want. Dedicate a roster spot to a defense but don't dedicate a defense to a roster spot.

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