While on divergent trajectories, advanced stats still see lots alike in these two teams
On October 23, the Seattle Seahawks and Arizona Cardinals mirrored each other for five quarters: The Cardinals punted three times in the first quarter, Seattle punted three times in the first quarter; in the second quarter Bobby Wagner blocked Chandler Catanzaro’s field goal attempt, a few minutes later Catanzaro successfully made a field goal try for the game’s first points; in the third quarter the action tightened up and slowed down: Arizona possessed the ball on just one drive that both started and ended in that period; at last, the Seahawks broke through in the fourth when they blocked Ryan Quigley’s punt and followed it with a Stephen Hauschka field goal to match Catanzaro’s; in overtime the Cardinals marched down the field and kicked a field goal on the first drive, Seattle answered right back with a field goal drive of its own; finally, Catanzaro missed a 23-yard kick after a 69-yard drive by Arizona and the Seahawks completed the dance with a 70-yard drive and a 27-yard miss by Hauschka.
At last the Blood Draw was over. It had been an exhibition of dominant defense and minimal offense. Neither side won, both sides were exhausted. In fact, both sides suffered losses against struggling teams the following week. The Cardinals featured 12 players on the injury report the Wednesday after the game, while Seattle’s list had 14. Michael Bennett aggravated his twisted knee to the point it required surgery and he missed five games. You could argue the Seahawks’ pass rush never totally recovered, although Bennett looked closer to his healthy self against a bad Los Angeles Rams line last week.
Seattle did bounce back eventually, winning a key road game versus the New England Patriots and going 5-3 overall since the duel in Arizona. The Cardinals, who were 3-3 entering the game, have been 2-5 since, without any road wins. I can’t prove the Seahawks extracted a permanent toll from Bruce Arians’s club, but what seems clear before the teams rematch their fateful epic this Saturday in Seattle is that Arizona and the Seahawks have traveled two different courses this season: Despite being equals for that one day in October, Seattle is four games up on the Cardinals and aiming for another Super Bowl run while Arizona is assured a losing record and eliminated from the postseason.
The Seahawks remain a top-10 DVOA team, while the Cardinals ranked 24th before losing to the New Orleans Saints Sunday. The Arizona defense that limited Seattle so severely is still strong, the third-most efficient according to Football Outsiders, but the Cardinals have given up 90 more points in 2016 than the Seahawks.
However, there is one metric that suggests the teams are still even:
Post week 15 team EPA plot. Up & right is good. This time w/ the Fisher Line and an illustration of how to tell the best and worst teams. pic.twitter.com/DFLs9if7Ap
— Brian Burke (@bburkeESPN) December 20, 2016
Brian Burke’s plot of offensive and defensive EPA shows that both teams are among very few in pro football this year in the “good” quadrant—with positive expected points added by both units. Indeed, the graph shows Seattle’s logo overlaid more or less right on top of Arizona’s. Given their shared station on the chart, relatively high up the defensive axis and barely beyond average on the offensive axis, they are by this category basically the same team.
For several weeks, as we tried to equivocate after the Seahawks’ yucky third and fourth losses, I have been as guilty as any of lumping this Cardinals matchup as one of a string of comparatively “easy” NFC West games Seattle faced down the stretch—although I’ve emphasized more specifically how it’s Arizona’s offense that fits with the pattern of lowly division opponents, I’ve relied on DVOA to make that case. While the EPA plot doesn’t say the Cardinals have a good offense, it makes a good visual demonstration for how much separation there is between Arizona and the San Francisco 49ers or the Rams who—no matter that the “Fisher line” indicates general mediocrity—are much, much farther from any representation of average.
Consistent with this visualization, Pro-football-reference’s figures group the Seahawks’ and Arizona’s offenses right next to each other in total expected points, at 14th and 15th in the league respectively, only about 1.3 points apart for the whole season. As you might expect, if you break it down by run and pass, the Cardinals’ running game featuring a full season of David Johnson is much more successful than Seattle’s stitched-together backfield, but Russell Wilson has a big edge over Carson Palmer to balance the offensive EPA.
PFRef shows less similarity for the defenses as Arizona, despite being ranked only two slots ahead of the Seahawks, gets credit for almost 15 more points generated by the defense on the year (which is why you can’t always use statistical rankings as approximations of relative magnitude—and you certainly shouldn’t average rankings across different stats or different years, because the distributions might wildly conflict or you get a Simpson’s paradox).
Nevertheless, this discrepancy in total expected points compared to Burke’s averages could be explained because the Cardinals have faced more drives than Seattle and slightly worse field position on average. That means Arizona has had more chances and more cause to “accumulate” expected points by limiting offenses (the Seahawks have allowed more yards and more first downs on fewer drives) without being more effective in aggregate. Indeed, as indicated by their true point differential, the Cardinals allow more than 0.3 more points per drive than Seattle and some kind of score almost 22 percent more often than the Seahawks (33.1 percent of drives to 27.2 percent).
Either way, I trust Burke’s formula (even if I can’t see his actual data) because his Advanced NFL Stats/Advanced Football Analytics site was one of the first to implement expected points and publicly explore their usage, before he adapted his methods for ESPN’s Stats & Info. And no matter if the EPA breakdown between Arizona and Seattle is perfectly even, you could still say both teams rather equally in the course of 2016 … exhibit dominant defense and minimal offense. Their profiles still very much mirror one another.
That doesn’t mean I expect the game to be another Blood Draw. I’ll give a much more detailed preview on Friday, as ever, but the short case for the Seahawks is that they’re playing at home. In addition to the difference in DVOA, even ESPN’s FPI which is highly influenced by Burke’s EPA and has kept the Cardinals in high regard despite their record gives Seattle a nearly 2-point edge on a hypothetical neutral field. The Seahawks lost Earl Thomas, but Arizona lost Deonne Bucannon and have a lot less to play for as they continue their 2016 implosion. Nevertheless, it’s worth noting that the overall performance of these rivals by one prominent measure has been a lot more similar than the standings or current trends indicate.
Even if the relationship has evolved into predator and prey, these birds were made for each other.