What constitutes an optimal defense play? Perhaps a low Vegas-projected over/under, being on a team projected to win the game, a defense that forces a lot of turnovers, and one going against a bad offense? Some of those overlap – Vegas projects bad offenses to score fewer points, of course.
The issue when picking a defense for NFL contests is that there are only a couple of “optimal plays” every week. And as we know about GPPs, ownership is everything. Picking the Seahawks against the Raiders is fine, but it isn’t so helpful when everyone in the world is also picking them. Thus, we need to find alternate plays that, while not as popular, still provide value.
So let’s look through our Trends tool and see what we can find. First, let’s start with a simple query – what’s the Plus/Minus for defenses (this data is all DraftKings, by the way) based on whether they’re the favorite or dog?
This is about what we’d expect – the people who set the lines in Vegas have billions of reasons to be accurate and that’s reflected here.
Let’s look at the dogs more specifically now. What about dogs on the road versus at home?
Okay, not so great. What about the spread? Underdog is a relative term – obviously there’s a difference between a one-point dog and a 10-point one.
As you can see, anything higher than about a three-point spread gets ugly for the defense. Ok, last query – what about implied points (we can calculate this using the moneyline and over/under) of the offense?
We get some slight positive value up until about 26 implied points and then it’s really ugly again. The lone high blip right at the beginning of the graph? That was the rare game in which the Seahawks were an underdog – last November against the 49ers when they scored 17 fantasy points.
We can definitely dive into this further and look at many more trends when it comes to defenses – and we will, don’t worry – but this is a good baseline to understanding which defenses to select. Drawing hard lines in the sand is almost always a no-no in DFS – the best players are usually the best because they’re very adaptable – but the line on defenses is fairly firm here. Should you always immediately cross out dog defenses every week? No, but I’d personally have to be very confident that Vegas missed a line to roster one.
