Defense Wins Games: In Real Life And In Fantasy Football

In real life NFL games, it’s well known that a good offense can only get you so far. It is the defense that not only wins games, but championships. Could the same thing happen with fantasy football? In our NFL preseason thinking, we recommend putting off drafting a defense until the later rounds because you can still get good value late in the draft. However, while there may still be good value in the later rounds, the question is: how essential is a good defense to winning in fantasy football?

To explore this, we looked at 10 random Yahoo head-to-head leagues and looked at how often a team wins their weekly matchup when their defense scores 10+ points. Of the 200 games we saw 140 classified, that is, one of the team’s defenses scored more than 10 pts. Remarkably, in those games where a team’s defense scored more than 10 points, the winner held a 44-6 record for a staggering 88% winning percentage. Numbers like that are very compelling: essentially, if your defense can put up points more often than not, you’ll get the win.

Now that we’ve established that a strong defense can make the difference between winning and losing, how important is it to write a top-notch defense? Can you hit the holy grail of 10 weekly defensive fantasy points more consistently by playing matchups than by drafting a solid defense? To see this, we took a look at the top 5 ranked defenses from the preseason live drafts and compared how those units performed to the top 5 defenses from ranked weekly matchups from weeks 1-4.

The top-ranked preseason defenses were the Pittsburgh Steelers, New York Giants, Baltimore Ravens, Tennessee Titans, and Philadelphia Eagles. These units averaged 8.39 fantasy points through the first 4 weeks of the season with a standard deviation of 4.30. Such a high standard deviation indicates that the performance of these “elite” units was patchy and inconsistent at best. While playing top-tier defense can land you a win on its own, they are likely to throw a bust out of a tough matchup and destroy your team.

The top 5 ranked matchup defenses obviously varied from week to week based on matchups, but they averaged 9.15 fantasy points with a standard deviation of 0.60. What this tells us is that playing matchups not only averages more points, but it’s a much, much more consistent way to achieve performance. Playing the matchups won’t result in the home run as often as top-tier defenses, but it will get you closer to the 10-point mark more consistently.

At the end of the day, our analysis supports our preseason assumptions that it’s better to write a defense late and play the matchups. The top ranked defenses can win you a game all by themselves, but there will be drastic ups and downs. Playing the matchups on defense is a great way to consistently rack up points and get closer to the holy grail of victory: 10 fantasy football points from your defense.