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

Three teams qualify as "chalky" this weekend by way of being average to above average defense with good matchups: New York, Buffalo and Miami. All three teams are facing opponents that have an implied total in Vegas of 19 or less and have all been favorable fantasy matchups for opposing defenses. The Giants, who rank seventh in Football Outsider's Defense Efficiency Ratings (DVOA), will be in Cleveland facing the Browns who have allowed the third most fantasy points per game to opposing defenses. The Dolphins, who rank seventh in DVOA, will host the Niners who have allowed the sixth most fantasy points per game to opposing defenses. And the Bills, who rank 16th in DVOA, will host the Jags who have allowed the fifth most fantasy points per game to opposing defenses.

The Bills may end up being the most highly owned of these three options, but lean towards the better defensive units of New York and Miami. Both defenses are cheaper than Buffalo on DK (with Miami being the cheapest there), and New York will cost you the same that Buffalo will on FD. If you play over on Fantasy Aces, the Bills are the cheapest of the trio there, so that's the best spot to use them in cash. 

Sneaky Options

This week there are two defenses that rank top five in DVOA and are facing opponents with the two lowest implied totals on Sunday, yet the three defenses mentioned above will likely be more highly owned.  Denver, home to Kansas City, and Baltimore, home to Cincinnati, rank second and fourth respectively in DVOA, but they won't be too higly owned because their opponents have only been average fantasy matchups for opposing defenses this season. Of the two, Balitmore is particularly interesting because they're cheaper across the board compared to Denver, and Baltimore's opponent, Cincy, is missing some key pieces on offense with A.J. Green and Giovani Bernard injured.

Bargain Options

If you're looking to go as cheap as you possibly can, consider Houston on DK at only $2,600. The Texans are a home favorite, albeit a slight one, and the Chargers only have an average implied total of 23. The Texans have an above average defense this season as they rank 12th in DVOA, and the Chargers aren't a bad matchup as all as they've allowed the tenth most fantasy points per game to opposing defenses.

On FD or Aces, the Saints are the cheapest possible option. The Saints defense is unquestionably bad as they rank 24th in DVOA, but their matchup with the Rams could cure what ails them. Only the Jets have allowed more fantasy points per game to opposing defenses, and the Rams have the sixth lowest implied total (19.25) on Sunday. Of the seven defenses cheaper than New Orleans on Sunday, all seven are facing teams with an implied total of at least 23.75. Over on Aces there are no defenses cheaper than the Saints as they literally cost the minimum price.