2021 Team Defense Strategy Guide

You’re down to the final 3 rounds of your draft. It’s time to start looking at the defenses. So what do you want?

Should you target the “best” available team D? Maybe. But we’ve seen historically that we can’t really count on a single defense to deliver us starter value all year. The best tend to produce top-12 fantasy weeks a little more than half the time. And a bunch more do so 7-8 times through the season.

So you’re not likely to build an advantage by targeting a “good” defense.

Take the Buccaneers, for example. They finished 2020 among the top real-life and fantasy defenses. But this year finds them taking on the Cowboys in Week 1 and the Rams in Week 3.

Would you rather trust the Bucs to win those early matchups … or find a less-heralded defense with a softer opening schedule?

Finding the Right Opponents

Before we get to seeking out those matchups to target, let’s look at the potential impact of those matchups.

I looked back over NFL.com’s fantasy points “allowed” numbers for team defenses, which date back to 2010. I lined up those 11 seasons of average fantasy points, got the median for each spot in the rankings and compared it to the overall median score. Here are the resulting impacts

The green section represents the 9 friendliest matchups for team defenses, with each spot adding 20+% to team-D scoring.

The red section represents the 9 matchup spots that have taken 20+% of the fantasy scoring away from team defenses. (And perhaps I should have included that last score from the white section in the red as well.)

In between sit the more neutral matchups. We’ll use this breakdown to help us separate the expected matchup groups for 2021 later in this article.

The Stats

OK, so it’s no big revelation that positive matchups help and negative matchups hurt -- or that we’d prefer to find the “help” over the “hurt.” But what signals should we be looking for as we head into a brand-new season?

Well, I dug into the numbers for this article 2 years ago, and refreshed them for this go-round. For the most part, nothing significantly changed.

Obviously, every stat included in your league’s D/ST scoring matters. But opponent points scored has proved to be the most closely correlated over time.

The orange line in that chart represents opponent scoring. It stands alone in negative territory because the correlation runs opposite to the other stat categories. The fewer points an opponent scores, the more fantasy points your defense gets. For every other category, of course, the more supplied the better for your defense’s scoring.

Since 2010, the numbers show a -0.775 median correlation between opponent points scored and team-D fantasy scoring. Here’s what those numbers look like for the other categories:

INTs: 0.596
Sacks: 0.541
Defensive TDs: 0.540
Fumble recoveries: 0.439

The past 4 years have actually seen a rise in the strength of the correlation for sacks (0.710) and INTs (0.645). We’ll have to see whether that trend continues, but it’s at least worth keeping in mind.

Even for that most recent span, though, opponent offensive scoring remains the most closely correlated to team-defense scoring.

We can clearly have all of this in mind as we navigate within a given NFL season, but what about heading into a new year?

As you might be able to tell from that chart, none of the stat categories here really gives us a clear year-to-year correlation. But the best signal from 1 year to the next has been scoring.

To put it another way, an offense’s prior-year performance in scoring gives us more of a signal for what’s coming next season than any of the other categories.

Now let’s get to what we all really came here for and see about the matchups for 2021.

Projecting the Matchups