As the final week of preparation begins for Super Bowl XLIX, we began a six-part examination on some key stories heading into the big game. Each part will use regression analysis, comparative analysis or playoff precedence to examine each chapter of this narrative. Today, in part one, we examine the biggest turning point of regression during the 2014 Seattle Seahawks season.
Heading into the 2014 season, the Seattle Seahawks enjoyed very high hopes of repeating as Super Bowl champions. Despite losing some key players to free agency, the team kept in tact its core of young, standout players. Regression analysis believed that the team would take a step back on defense, but one that wouldn’t prevent the unit from continuing to play elite football. Better yet, it also believed that the offense could improve with pass protection and penalty regression. We used this reasoning to pick the Seahawks for the repeat.
However, during the 2014 season’s early stages, the defense looked much worse than elite. The team held up well during home wins against the Green Bay Packers (36-16) in Week 1 and Denver Broncos (26-20 in overtime) in Week 3. It also allowed 24+ points five times in its first 10 games, going just 1-4 in those games. This led Seattle to own just a 6-4 record heading into the home stretch of the regular season, putting the defending champs in peril of even making the postseason.
The Seahawks failed to stop Jamaal Charles (25) in Kansas City Chiefs during a 24-20 loss. The defeat dropped Seattle to 6-4, but it was also the last loss of the Seahawks’ season. (photo rights to the Kansas City Chiefs)
Seattle responded well to facing its crossroads, winning the final six games of the regular season. This happened primarily due to the defense regaining its elite form. The Legion of Boom yielded all of 39 points during the six-game winning streak, and it allowed Seattle to clinch home-field advantage for the NFC playoffs. Clearly, regaining defensive form in that concluding stretch of the regular season got the Seahawks to this point. How exactly were the Seahawks able to achieve this turning point? Regression provides the answer.
Seattle’s Top Regression Factor in 2014: Red Zone Defense
Seattle’s defensive improvement obviously coincided with its improved scoring defense. With a deeper look and analysis into the Seattle defense, we’ll see which facet of the game the Seahawks best improved at to improve the whole unit. Our first intuition into determining the genesis of Seattle’s improvement is to look at the team’s Defensive Passer Rating. According to Cold, Hard Football Facts, the passer rating battle (re: Passer Rating Differential) has an 81.8 percent correlation to victory and a 61.0 percent predictive rate of victory this regular season and postseason combined. Therefore, we know that this should have a strong impact on Seattle’s chances of winning.
Check out how Seattle’s Defensive Passer Rating progressed throughout the season:
- Games 1-6 (23.5 PAPG): 142-of-208 (68.27%) for 1382 yards (6.64 YPA), 12 touchdowns and two interceptions (101.88 rating)
- Games 7-10 (18.5 PAPG): 76-of-123 (61.79%) for 756 yards (6.15 YPA), three touchdowns and four interceptions (73.76 rating)
- Games 11-16 (6.5 PAPG): 95-of-176 (53.98%) for 966 yards (5.49 YPA), two touchdowns and seven interceptions (57.15 rating)
- Postseason (19.5 PAPG): 42-of-70 (60%) for 424 yards (6.06 YPA), three touchdowns and four interceptions (67.80 rating)
As you can see, the passing numbers improved throughout the regular season and barely declined in two postseason games. However, there wasn’t a notable change in scoring defense, except for Games 11-17. Therefore, there must be a subset stat that continued to play a role from the seventh game to the 10th game. When there’s a stronger improvement in overall efficiency than scoring efficiency, key subset stats like third down defense and red zone defense come to mind. With a 39.74 percent third down efficiency on defense, that isn’t a number that seems to be holding back the Seahawks. The red zone defensive efficiency tells a different and more telling story.
- Games 1-6 (23.5 PAPG): 18 opponent red zone opportunities; 13 touchdowns, five field goals (105 points, 5.83 PAPO)
- Games 7-10 (18.5 PAPG): 11 opponent red zone opportunities; seven touchdowns, three field goals (58 points, 5.27 PAPO)
- Games 11-16 (6.5 PAPG): Eight opponent red zone opportunities; two touchdowns, five field goals (29 points, 3.63 PAPO)
- Postseason (19.5 PAPG): Seven opponent red zone opportunities; three touchdowns, three field goals (30 points, 4.29 PAPO)
The red zone defense showed significant improvement over the past eight games in total, so the increase in points allowed in the postseason merely has to do with the better opponents and higher stakes. It also has part to do with the potential outliers that can be present in a small sample size. For this case, the Packers converted three field goal attempts during scoring drives that never reached the red zone. Luckily, the Seahawks prevented the big touchdown pass, something they haven’t allowed since Week 14. Seattle allowed 76.77 percent of its points in the red zone in regular season and 76.92 percent of its points in the red zone in the postseason.
Clearly, we see that Seattle’s true turnaround to becoming a Super Bowl contender began in the team’s 11th game of the season. This turnaround clearly coincides with in-season regression to the mean for the Seahawks red zone defense. Through 10 games, the Seahawks allow nearly one point more per red zone opportunity (5.62) than the league averaged for the entire regular season (4.74 PAPO, per Football Outsiders). That average would’ve easily ranked dead last in the NFL if it withstood for the whole year, which is far from the normal output by a great defense. To compare, the six-game average to close out the regular season would’ve easily topped the league. The latter ranking is certainly more like what’s expected from a great defense.
More over, the Seattle red zone defense improved on a play-by-play basis as well. According to Aaron Schatz of Football Outsiders, the Seahawks reversed their fortunes in Defensive DVOA and Success Rate. They ranked 31st and 32nd in the respective areas through Game 10 (Week 11) and ranked fourth and fifth in the respective areas over the final six weeks of the regular season. Seattle also improved from 3.52 yards allowed per red zone play to 2.22 yards allowed per red zone play.
(Note: The points and touchdowns allowed per red zone opportunity are undeniably inaccurate for Weeks 12-17 in the Football Outsiders article. There is no possible way a team that allowed three touchdowns in the final six weeks can have a red zone touchdown percentage of 44 percent in that span. To get that percentage, a defense would at least need to allow four touchdowns in that span. Also, Seattle’s PAPO is incorrect in the drive stats we previously linked from Football Outsiders. Due to a failed two-point conversion by Green Bay in Week 1, Seattle allowed 5.19 PAPO, not the 5.22 PAPO claimed in that link.)
For Seattle to rank among the worst red zone defenses en route to a 6-4 start was highly unexpected. Fortunately for the Seahawks, they pounced on the opportunity to regress in this area. As a result, they haven’t looked back. The defense looks very strong during the eight-game winning streak, even better than what the postseason PAPG suggests. As long as Seattle can keep up its recent elite ways in the red zone on defense, the NFC representatives will be in peak form to match-up well in Super Bowl XLIX.