Prime-Time Props — Thursday Night Football, Week 1
Prop God
Part of the launch of FTN’s Premium Stats and Fantasy HQ was box defender stats. The box on defense is an imaginary line set to define players near the line of scrimmage. The concept is that the more defenders in the box, the harder it is to run the ball. While this is almost always the case, loading the box can lead to bigger runs when the ball carrier breaks to the second level, because there aren’t defenders to help chase him down or cut off his angles — see the Jaguars trying to catch Derrick Henry in December.
What does box defenders mean?
When defenses have a light box, it means six or fewer defenders are in the box, giving the offense an easier path to run the football. Seven is considered standard with a base defense — four linemen and three linebackers — but in today’s passing league the new base defense is nickel defense (five defensive backs on the field). Don’t tell NFL coaches this though, as most still played with three linebackers on the field more often than three corners — in fact, only the Broncos. Rams, Saints, and Panthers had more snaps with six in the box than seven last season.
Typically, when teams go with fewer than six in the box they are playing in obvious passing situations — only the Giants saw more than 40 rush attempts against a five-man box, and their 10 attempts with four in the box led the league last season. If you look across total defenders in the box, you see that yards per carry drop the more defenders you add.
How can I use box defenders in fantasy football?
Beyond the raw data, you can start to understand team philosophies. Wade Phillips was one of the first coaches to understand that running is far less efficient than passing so you try to play with a lighter box to dare teams to run it against you. The more the offense runs, the greater advantage a defense has in putting them in worse down and distances.
Teams like the Broncos, Rams, Patriots and Giants — four of the league’s top defenses — consistently filled the box with only six defenders, and all four finished with defenses in the top half of the league against the pass; the Rams were the league’s top defense.
A team like the Jaguars — in part due to game scenarios and in part due to how bad their run defense was — consistently added help to the box. They played 222 snaps with eight defenders in the box, 44 more than the next-closest team. On those attempts they only allowed 3.9 yards per carry compared to 5.0 with seven in the box and 5.4 with six. We saw this play out in the first game against the Titans, where Derrick Henry consistently faced eight men in the box and was held to 84 yards on 25 carries — just 3.4 yards per carry.
Box defender stats help determine fantasy football matchups
One great way to use these tools is to take a deep dive in the matchups. Understand not only what philosophies a coach may try to use — if he will bait a team in the run game, if he will load up the box, or if he just plays to the situation — but if it matters. There are some run defenses that were so bad it didn’t matter what they did — I am looking at you, Cowboys and Texans. The Cowboys allowed a league-high 4.7 YPC with five defenders in the box, 5.0 with seven in the box, 5.0 with six, and 5.2 with five. No matter how many bouncers the Cowboys brought to the party, every team had a good time against them. Same goes for the Texans allowing the most yards per carry against eight-man boxes, most against seven-man boxes, and the second most against six-man boxes. With very little help added this offseason and projected to be the worst team in football, teams are going to run against them like they are in the Tokyo Olympics.
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