The Chiefs finished 14-2 for the most regular-season wins in franchise history and the most ever for Andy Reid. But after a Bill Belichick-ian against-the-spread run to start the season, something weird happened about halfway through: They stopped covering.
From Week 9 on, the Chiefs went 1-7 against the spread (ATS) despite going 7-1 straight up (SU), winning games by margins of two, four, three, six, six, three and three before taking Week 17 off. For the season, the Chiefs finished 7-9 ATS, their first losing ATS record in eight seasons under Reid, who led them to a 65-44-3 (59.6%) ATS record from 2013-19.
They say "good teams win, great teams cover." So does that mean the Chiefs aren't great? Let's take a look.
Do Super Bowl Teams Have Winning ATS Records?
If the Chiefs go on to win Super Bowl, they would become just the second team to win it after finishing the regular season with a losing ATS record since 2000, joining the 2012 Ravens as the only other team to do it. It's never great to be in the company of Joe Flacco, but Patrick Mahomes is no Flacco, so it's hard to view this as anything more than the answer to a trivia question.
But let's look at it another way: Despite the league-best 14-2 record, the Chiefs finished sixth in average point differential (6.9) behind the Ravens, Saints, Packers, Bucs and Bills — and only 0.4 points ahead of the Steelers, who crumbled against the Browns in the Wild Card Round.
Point differential tends to be more predictive than win-loss record, so what does the Chiefs' good-but-not-great point differential mean for their Super Bowl chances?
Not much, it turns out: Since 2002, the average rank in point differential of teams that won the Super Bowl is 5.2. Seven of those 18 teams (or 38.9%) finished with a point differential of 6.9 or less.
ATS Records of Past 20 Super Bowl Winners
So Why Aren't the Chiefs Covering?
In a nutshell, the Chiefs have struggled in many areas of situational football this season. It hasn't cost them games (yet), but it has created enough of a swing in the final score to cost them covers.
Red-Zone Defense
The Chiefs allowed an NFL-worst 76.6% red-zone touchdown conversion rate this season. And even though they have made 12 more red-zone trips than their opponents, their opponents have just as many red-zone TDs (36).
This has been especially apparent over the second half of the season when they stopped covering: From Week 9-16, the Chiefs allowed opponents to convert for TDs on 18-of-21 red trips (85.7%).
In their nine ATS losses, they've allowed opponents to convert on 24-of-30 red-zone trips, including 20-of-24 excluding Week 17, when they rested their starters. In their seven ATS wins, the Chiefs still allowed a 70.6% conversion rate, which is still not good, but a while lot better than 80% plus.
Short Yardage
Despite drafting Clyde Edwards-Helaire, signing Le'Veon Bell midseason and giving downhill runner Darrel Williams way more burn than he deserves, the Chiefs have been terrible in short yardage.
They rank dead last with a 51.0% power success rate, which measures how often a team converts with two or fewer yards to go on third or fourth down and all goal-to-go situations from the 2-yard-line or in, regardless of down.
Compounding matters, the Chiefs also rank dead last in power success rate allowed on defense, allowing opponents to convert at a league-high 78% clip. Short-yardage plays can be the difference in extending a drive or turning it over on downs, or between a TD and a field goal, or even a TD and a turnover on downs, so it's no surprise that the Chiefs' lack of success in this area on both sides of the ball has coincided with their ATS drop-off.
Special Teams/Field Position
From 2013-19, you could count on death, taxes, and the Chiefs fielding an elite special teams unit. But in 2020, they were merely average. Below are their ranks in Football Outsiders' special teams DVOA by year:
- 2013: 1st
- 2014: 3rd
- 2015: 9th
- 2016: 1st
- 2017: 4th
- 2018: 2nd
- 2019: 2nd
- 2020: 17th
The Chiefs are one of only seven teams with a punt return TD this season — a 67-yarder by Mecole Hardman in Week 12 against Miami — so it's surprising that punt returns are the biggest culprit in terms of expected points added (EPA) lost (-5.2, fourth-worst). But even with that long scamper, the Chiefs' average of 5.8 yards per punt return ranks 26th — 3.0 full yards below league average. Remove the 67-yarder, and Hardman has just 106 yards on his other 24 returns.
Demarcus Robinson got two cracks at it and was even worse, getting stopped for no gain on his first return then losing 13 yards on his second. Tyreek Hill — who owns a monstrous 11.7 average and four TDs on 86 returns but has long ago been deemed too valuable for the job — returned only one punt all season (and naturally, that got stopped for no gain as well).
Field position is one of the hidden edges that can help teams cover, and this season also marks the worst in the Reid era.
- 2013: 33.4 (1st)
- 2014: 29.3 (8th)
- 2015: 31.3 (3rd)
- 2016: 30.5 (4th)
- 2017: 29.1 (13th)
- 2018: 30.9 (3rd)
- 2019: 28.8 (9th)
- 2020: 28.2 (20th)
We're generally talking about a difference of a yard or two, but every yard is worth points, and there are an average of 11 drives per game, so this is another one of the subtle edges the Chiefs are losing out on this year that they enjoyed previously.
Fourth Quarter Defense
The Chiefs are allowing 9.2 points per game in the fourth quarter this year, sixth-most. This has been an issue since before defensive coordinator Steve Spagnuolo got there — they ranked 25th in 2017 with 7.0 and 29th in 2018 at 8.7 before posting a respectable 13th (5.8) in Year 1 under Spags.
But the Chiefs ATS dominance under Reid was built on shutdown fourth-quarter defense, especially pre-Mahomes, finishing first in 2013 (4.0) and 2014 (3.2) and seventh in 2015 (5.2) and 2016 (5.2), though they did dip to 20th in 2018 (7.0).
This season, the Chiefs' ranks in DVOA by quarter are 15th, 26th, eighth and 28th, respectively. They're peaking in the third quarter, suggesting that the halftime adjustments from Spagnuolo are sound, more or less.
Defending the Middle
The most efficient place to throw in the NFL is the middle. According to Football Outsiders, passes to the middle have a +8.4% DVOA, compared to -0.6% to the left and -3.6% to the right. The Chiefs rank fifth-worst with a 26.6% DVOA on passes to the middle, the worst of any remaining playoff team.
According to Sports Info Solutions, the Chiefs have spent the second-most snaps in a two-deep shell — which leaves the middle open — and have paid the price. The Chiefs rank fifth-worst in yards per attempt (8.38) and fourth-worst in QBR (101.75) while in Cover 2. No team has allowed more than KC's 77.5 yards per game in Cover 2.
The Chiefs' ATS drop-off coincided somewhat with Tyrann Mathieu playing farther from the line of scrimmage. After playing 4.0 snaps per game lined up at free safety in his first nine games, Mathieu has played 20.3 snaps per game at free safety over his last six. While that has led to four picks, the defense as a whole hasn't been able to capitalize. Even with Mathieu taking the place of struggling safety Juan Thornhill while being replaced in the slot by impressive rookie L'Jarius Snead, there are still weak defenders underneath due to injuries at linebacker.
Thornhill's struggles have impacted the defense, which has fallen from seventh last season to 16th this season in DVOA against the pass. His Pro Football Focus grade has also regressed from 71.5 last year to 52.8 this year, and his yards per target has doubled from 5.1 to 10.0.
The Chiefs like to play with two safeties deep because they don't mind if teams run, and they want to give their unheralded cornerback group help deep, which has been effective — they've raked top-two in fewest yards allowed to wide receivers in both years under Spagnuolo.
The philosophy funnels action to linebackers in coverage, especially with Mathieu playing near the line of scrimmage, but the linebackers give up a ton of production, even if it's by design. According to PFF, four of the Chiefs' five linebackers — Darius Harris (154.2), Ben Niemann (121.4), Damien Wilson (117.9), and Anthony Hitchens (109.1) — have allowed a passer rating of at least 109.1 this season, with only Willie Gay Jr. (92.4) posting a respectable mark.
The Chiefs Are Still Great, Just Not Quite as Great
Overall, the Chiefs have fallen from first in total DVOA in 2018 (33.2%) to fourth in 2019 (30.1%) to sixth this season (19.5%). It's not a huge drop-off in terms of rank, but it does represent a drop-off of more than 10% in per play efficiency.
Long gone are the days when the Chiefs would take the market by surprise with Alex Smith at the helm, so this subtle but discernible drop-off in per-play efficiency as the Mahomes era has worn on explains their decline in ATS win rate. But they have Mahomes, so they'll probably still win the Super Bowl.
