What is line movement? During the NFL season, bookmakers usually post a spread with a total as early as possible to begin taking bets. For Week 15, these lines were posted as early as Sunday night and have since been adjusted. They are adjusted in the following hours and days due to transactions, injuries, weather reports, large bets on one side -- any number of things.

Washington is a 4.5-point favorite against the Arizona Cardinals. Washington opened as 4.0-point favorites and have crept up to 4.5-point favorites. Also, the total in this game has dropped. The game opened at a total of 44.0 points but has plunged two points to 42.0 at Pinnacle, per Sports Insights. The line could vary as we head into the weekend, but this drop in the total bodes well for the Washington D/ST.

Last year, I wrote about how line movement affects defensive performances, and when the total fell two points or more in 2015, the defenses involved averaged 8.30 fantasy points per game. Also, when the total was 39 to 42 points, the average D/ST score was 8.06 fantasy points per game.

The Washington D/ST is priced at $4,500 on FanDuel, which ranks 12th among defenses. The Cardinals may have won last week, but they didn't score any touchdowns. Washington's defense hasn't been great this season, but since they are in a prime spot, they are worth starting in tournaments.