What is DVOA?
DVOA is a statistic created by Football Outsiders and stands for Defense-adjusted Value Over Average. Translation: DVOA shows how good (or bad) you are compared to an average team. DVOA is a percentage, with a league-average DVOA being 0%.
How is DVOA calculated?
Put simply, DVOA is calculated by comparing every single play in the season to a league average baseline. It’s then adjusted for strength of opponent, game situation, and field position. Additionally, DVOA values successful plays more than other plays. A successful play is considered to be a play that gains 45% of the yards needed for a first down on first down, 60% of the yards needed on second down, and 100% of the yards needed on third and fourth downs. In other words, if you gain eleven yards on a 3rd-and-16, it matters a lot less than gaining six yards on a 3rd-and-4. DVOA is able to take this difference into account, unlike simpler statistics.
How can I interpret DVOA?
On offense, a positive DVOA means that you’re better than average while on defense, a better than average team has a negative DVOA.
What’s the reason for this discrepancy?
DVOA is a measure of how many more points you create than an average team. On offense, the best teams create more points than an average team, so their DVOA is positive. However, on defense, the best teams prevent more points than an average team, so their DVOA is negative, because they create “negative points”.
Why is DVOA better than simpler statistics like points scored and allowed?
DVOA is better than simple points scored and allowed because of its increased accuracy and predictive value.
How does DVOA gain its accuracy?
As mentioned before, DVOA is adjusted for a number of factors. In addition to the three mentioned above, DVOA is based on plays, rather than points. This is important in a couple of ways.
One, if the offense throws a pick-six, that shows up as points allowed for the defense. However, it was obviously the offense’s fault, not the defense’s. Simple statistics attribute those points to the defense, but more advanced metrics like DVOA correctly assign blame to the offense.
Two, while points allowed only records drives that end in scores, DVOA takes note of every play on every drive. For instance, let’s say that Team A gives up fourteen points and 250 yards per game, while Team B gives up fourteen points and 350 yards per game. By simple measures such as points allowed, Team A and Team B have equal defenses. However, by DVOA, it’s clear that Team’s defense is better than Team B’s on a play-by-play basis.
Are there any other details I should know?
There’s one important factor we’ve only mentioned so far, and that’s DVOA’s adjustment for field position. If your quarterback throws an interception and your opponent starts their position on your one yard-line, then it’s very likely, even if your defense is spectacular, that you’ll give up a touchdown. The opposite is true as well. DVOA gives your offense more credit for long drives than for possessions that begin in your opponent’s red zone.
Simple statistics don’t measure that. To them, a one yard drive for a touchdown is equal to a methodical fourteen play, ninety-two yard drive for a score.
There are various other permutations of DVOA that we won’t discuss in this particular article. One notable one, however, is DYAR, which is DVOA but in a cumulative statistic, rather than a rate one.
In future football articles, we’ll be using DVOA a lot more, and I hope you find this FAQ useful so you’ll be able to be a more discerning football fan. And, even if you still don’t understand it, it’s a fancy sounding statistic with an acronym; just using it in a sentence makes you sound about three times as smart.
Pingback: How Good is Denver’s Defense? | Sushi on Sports