The key with defenses is finding defenses that will face a lot of passing plays. Fantasy point-scoring events like interceptions and sacks occur exclusively on passing plays, and fumbles actually occur more on passing plays than running plays. Defensive touchdowns are difficult to predict, but they're also more likely to occur on passing plays with 53 pick sixes last year compared to only 33 scoop 'n scores.
One of the best ways to identify defenses that will face a lot of passing plays is identifying Vegas favorites, preferably home favorites. And obviously the lower the opponent's implied point total, the better the matchup for the defense.
Premium Options
Minnesota is unquestionably the chalk defense play this week. Their opponent, Chicago, has the lowest implied total by more than a full point. We all know Minny's defense is elite, but, to illustrate the point, they rank second in Football Outsiders' defensive DVOA. The problem here is that Minny-Chicago is the Monday night game, and with the major sites now emphasizing Sunday-only contests, Minnesota may not be an option for a lot of players.
The Sunday-only chalk is Denver. The Broncos are at home against the Chargers, who have the third lowest implied total of the week. The Broncos rank fifth in DVOA, so this is clearly a good defense with a favorable Vegas line. That said, it's a middling matchup against a San Diego team that ranks ninth in offensive DVOA and allows only an average number of fantasy points per game to opposing defenses. Denver is likely going to be the highest owned defense in Sunday-only contests according to our Ownership Forecaster, so feel free to fade them in GPPs.
Sneaky Option
This category is reserved for good defenses that may be overlooked in a given week for whatever reason, providing you with the opportunity to roster a really good unit with a lower ownership rate.
Seattle is the team that best fits that bill on Sunday. The Seahawks rank third in DVOA and seventh in fantasy scoring, so they certainly fall into the category of a good defense. They should not be an overly popular play this week in New Orleans against a Saints team that ranks fourth in offensive DVOA and that has historically been better at home. But an Atlanta defense that ranks 26th in DVOA went to New Orleans earlier in the season and came away with six fantasy points, so it's not as if it's impossible for a defense to have a decent day in New Orleans.
Vegas gives the edge to the Seahawks in this game, and they have New Orleans with a slightly below average implied total. That somewhat fits the mold of a game situation in which the Saints have to throw the ball at a healthy clip, giving a good Seattle defense the chance to make fantasy scoring plays. The Hawks certainly aren't a cash play because that's not what this section of the article is for. But if you're looking to get contrarian, Seattle has the talent to have a big day against anyone.
Value Options
Dallas isn't one of the cheapest options available on Sunday, but they're at least a value in relation to Denver. I mention Denver because Dallas is the only team playing on Sunday whose opponent has a lower implied total than Denver's opponent. Dallas' opponent, Philadelphia, has an implied total of just 19.5. That's obviously a plus for Dallas as is the game being played in Dallas. Dallas isn't a great defense as they rank 20th in DVOA, but the Eagles aren't a great offense either. Philly's offense has struggled lately, and they've slipped all the way to 24th in offensive DVOA.
Dallas will likely be around the fourth or fifth most popular defense on Sunday, and they'll probably be a bit more highly owned on FD given that they're priced a bit better there. That level of ownership probably doesn't preclude them from GPP use, and they're obviously a cash game option with the Vegas line being so favorable to them.
As for the cheapest possible options, Houston at $4,300 on FD is about as cheap as you'd want to go. Houston's defense obviously isn't the same without J.J. Watt, but they still rank 12th in DVOA. They're in a decent spot according to Vegas as they host Detroit who has the seventh lowest implied total on Sunday. The Lions are a below average matchup for opposing defenses, but middling defenses like Tennessee and Chicago have had decent days against them.
On DK, San Diego is a nice cheap option at only $2,400. The Chargers defense is probably underrated as they rank eighth in DVOA and are 10th in fantasy scoring. Their opponent, Denver, has an average implied total, and they've only been an average matchup at best for opposing defenses. But we're not saying the Chargers are an elite play. We're just saying they shouldn't be the third cheapest defense on DK on Sunday.