The Seahawks' Defense Is Even Worse Than Expected Without Earl Thomas

Right when Earl Thomas hit the turf, you knew it was bad news.

Thomas sat up, grabbed for his leg, and then promptly returned to his back. As he collapsed, so did the hopes of the Seattle Seahawks' secondary.

Just the previous week, Tampa Bay Buccaneers wide receiver Mike Evans had ripped the Seahawks on 8 receptions for 104 yards and 2 touchdowns while Thomas sat due to another ailment. There was always the possibility for that to happen again if Thomas missed more time. That possibility has largely been a reality ever since they placed Thomas on injured reserve with a broken leg.

Let's take a look deeper inside the numbers to see how the Seahawks' pass defense has performed since Thomas' season-ending injury using numberFire's Net Expected Points (NEP), the metric we use to track the efficiency of both teams and players with the team totals being adjusted for strength of schedule. This will tell us the expected points a team has added on each play for a specific time span, giving us a true glimpse into the differences between the Seahawks' defense with Thomas and without him.

Seattle has a rough matchup on tap this week against Matt Ryan and the Atlanta Falcons. Can they overcome it without their star safety? Let's check it out.

As Bad As Expected

Whenever we've got a situation where a team loses an integral part of its strongest unit, you'd expect their overall effectiveness to lag. The Seahawks without Thomas have been no exception.

Here's a look at their NEP splits in the 11 games he has played this year compared to the six games (including the team's wild card victory over the Detroit Lions) he has not. Passing NEP is the expected points added on each pass attempt, accounting for expected points lost due to sacks, interceptions, and incompletions. Success Rate is the percentage of drop backs that result in positive NEP.

They allowed more Passing NEP in six games without Thomas than they did in 11 games with him despite facing 248 fewer drop backs. That's just a wee bit concerning.

What makes this all worse is looking at the competition they faced in their time without Thomas. This sample included matchups against studs like Jared Goff and Case Keenum, Colin Kaepernick, and an injured Matthew Stafford. The one top-flight passer they faced was Aaron Rodgers, and he shredded them for 246 yards on just 23 attempts with 3 touchdowns and no interceptions.

Once we account for this below-average competition, things get even more bleak. From Week 12 on, a span in which Thomas played just 17 snaps, the Seahawks ranked 29th in Adjusted Defensive Passing NEP per play. The only teams below them were the Los Angeles Rams, Cleveland Browns, and San Francisco 49ers. It's entirely possible that we somehow underestimated how important Thomas was to the team.

One area in which the Seahawks stood out above the crowd when Thomas was healthy was limiting teams on passes deep down the field. Because Thomas is a safety, you'd assume those abilities would take a hit when he went down, and you'd be absolutely correct.

Here are splits to track how the Seahawks' opponents performed on passes at least 16 yards down the field with and without Thomas. For some additional context, the league averages for each metric on long passes are also included.

Although the Seahawks were still better than a league-average team on deep passes, they were infinitely worse than they were when Thomas was healthy. And remember, this is while facing a whole load of low-level competition. Matt Ryan does not qualify as such, and it could give the Seahawks with a world of hurt on Saturday.

Ryan's Strengths Present Issues

Overall this year, Ryan was a straight up beast in the efficiency department. He led all quarterbacks in Passing NEP per drop back of the 39 who had at least 100 drop backs, and he had over 27 more Passing NEP than any other player in football. A lot of this came on passes deep down the field.

For the season, Ryan attempted 97 passes that were at least 16 yards beyond the line of scrimmage. They resulted in a 57.73% Success Rate, blowing the league-average mark of 41.25% right out of the water. The next-highest mark for any quarterback with at least 70 deep passes was Andrew Luck at 52.34%. This is an other-worldly number.

Ryan's proficiency when throwing deep -- not shockingly -- was even higher when he was at home. His Success Rate jumped up to 58.14%, and his Passing NEP per attempt increased to 1.12 from 0.97 on the road. That's largely what you'd expect while playing inside a dome, which is where this weekend's game will be.

When these two teams squared off back in Week 6, the Seahawks were largely able to hold Ryan in check on these long passes. He attempted nine passes at least 16 yards down the field, and four were caught for a 44.44% Success Rate and 0.38 Passing NEP per attempt. Two resulted in touchdowns, but another was intercepted. The man who got that interception? It was Earl Thomas.

Now, the Seahawks go on the road to face Ryan without Thomas patrolling the field. This is a way more difficult assignment than they faced earlier in the year, and they're going to need to right the ship quickly if they want to advance to the conference championship.

Conclusions

Thomas is a phenomenal player, and people knew the Seahawks would struggle with him out of the lineup. But struggles this immense would have been harder to predict.

When you adjust for opponents, the Seahawks have had one of the worst pass defenses in the entire league since Thomas' injury, besting only teams who scraped the bottom of the barrel. These struggles were even more defined on deep passes, an area where Ryan figures to test them this week.

Outside of a matchup with Rodgers in Week 14, this will easily be the hardest task the Seahawks have faced since Thomas went down. Unfortunately, it also comes at the most critical time of the season. The Seahawks' secondary has gone from being a strength to a liability, and one fluky play in which their star safety landed on injured reserve could wind up costing them their season.