The Anatomy of an NFL Playoff Upset

There are surprises hidden inside of every iteration of the NFL Playoffs. They come in varying shapes, styles, and sizes, but they all have the same consequences: a favorite bids farewell, and an underdog lives another day.

As we embark on the precipice of another playoff journey, I got to wondering about what makes up the anatomy of an NFL Playoffs upset. Maybe I could trace some trends from playoffs from the recent past, it might shed some light on how these major moments come to be. Perhaps this could hint at which playoff personalities may fall victim to a similar fate this winter. If nothing else, it might be fun to dig up some old trauma for a handful of NFL fan bases. Football-focused schadenfreude never killed anybody.

For this exercise, I wanted a wide enough berth that I had plenty of data points while maintaining relevant results for the modern NFL. Plus, I didn’t want to overwhelm myself with too much. I am only one man. Five years felt like an appropriate timeline to operate within.

In the last five NFL postseasons, the underdog has overcome the favorite on 23 separate occasions. Twice, that occurred in the Super Bowl; the Chiefs were 1.5-points underdogs to the Eagles in last year‘s Super Bowl, and the Chiefs were 3-point favorites prior to Tampa Bay’s demolition of them in Super Bowl LV. The rest came in rounds previous.

But not all 23 of those technical upsets were all that surprising. Most had small lines, displaying a narrow bend one way. That is not exactly what comes to my mind when I think “upset.” So, I cut out any contest in which the underdog was considered to be within three points or fewer of the favorite. I tunneled my vision toward only the matchups with lines larger than a field goal. That left me with nine pairings to parse: 2023 Bengals at Bills, 2022 Bengals at Chiefs, 2022 49ers at Packers, 2022 Bengals at Titans, 2021 Browns at Steelers, 2020 Titans at Ravens, 2020 Vikings at Saints, 2020 Titans at Patriots, and 2019 Eagles at Bears.

What do these games have in common? Where do they depart? What can we learn from their existence? Our finding could come in handy when the Splash NFL Playoffs Pick X contests roll around. Let’s dive in.

Getting Hot at the Right Time

Momentum is one of sport’s most crucial intangibles. It stands to reason that a team entering the playoffs on a high note would be more likely to continue that into the postseason, underdogs included. There seems to be some evidence of this truth in the last five years.

The 2022-23 Bengals carried an eight-game win streak with them into the playoffs, and they overcame a 5.5-point spread against the favored Bills in the Divisional Round, 27-10.

The 2021-22 49ers went 7-2 in their final nine contests, including a marquee win to end the campaign over the Rams, eventual-Super Bowl champs. San Francisco was a 5.5-point underdog at the Packers in the Divisional Round but won anyway, 13-10.

The 2018-19 Eagles closed out the campaign with five wins in six tries to salvage its once-4-6 record before shocking the 6.5-point favorite Bears in the Wild Card Round, 16-15, generously benefiting from the now-famous double doink.

The 2019-20 Titans were 4-5 through Week 9, then won four in a row and clinched a playoff berth in the final week of the regular season with a decisive 21-point road triumph at the Texans, that year’s AFC South champions. That Tennessee team went on to contribute two major upsets to this list: first beating the Patriots and a 4.5-point spread in the Wild Card Round, 20-13, then next wrangling the Ravens and a 10-point spread in the Divisional Round, 28-12. The Titans’ upset of the Ravens that year is the biggest of the half-decade.

The 2021-22 Bengals took three-straight for themselves late on in the schedule, including a defining home victory versus the Chiefs in the penultimate week to secure the AFC North title. Like the Titans before them, the Bengals achieved two upsets worthy of study. Poetically, Tennessee was Cincinnati’s first victim, falling 19-16 to the away side despite a 4-point line in its favor. More politically, the Bengals beat the Chiefs again, this time at Arrowhead, in the AFC Championship Game, 27-24, laughing at their status as 7-point underdogs prior to kick off.

There has only been one glaring exception to the momentum angle in the last five years. The 2019-20 Vikings lost the last two games of the regular season and were 2-3 in their final five, costing them any hope of the top spot in the NFC North. Minnesota was subsequently a 7.5-point underdog at New Orleans in the Wild Card Round but stunned the Saints and the books, 26-20.

That’s not enough for me to decry the impact that being hot can have this time of year, though. There is a healthy amount of evidence that shows that an underdog that has been finding itself on the right side of games lately is a dangerous one. Any favorite would be wise to handle those underdogs with extra care.

It’s Better If They Don’t Know You

Don’t let previous matchups between teams pitted at one another cloud your judgment too much. There is little to suggest it means anything for a major underdog’s likelihood to David a Golliath.

The 2021-22 Bengals didn’t play the Titans in the regular season but bested the Chiefs weeks before doing it again to punch their Super Bowl ticket. The 2020-21 Browns went 1-1 against the Steelers in the regular season, getting smacked by 31 in October before enacting revenge in Week 17. They then ended Pittsburgh’s season in the Wild Card Round seven days later, 48-37, in the face of a 5-point spread.

It was a different story for the 2021-22 Niners. They surrendered to Green Bay by two points in Week 3, but that outcome didn’t impact their joint reintroduction in the playoffs.

And that’s it. None of the other major upsets from the last five years were rematches. The Bengals and Bills were supposed to play in Week 17 of the 2022-23 campaign, but extenuating circumstances canceled that affair. For the most part, these major upsets have not been centered around teams that know one another.

Maybe the conclusion to draw is that a misunderstood underdog is a dangerous one. When a favorite has familiarity with its foe, the element of surprise disappears. Past results indicate favorites are still vulnerable even if they have played their underdog adversary, but zero shared history is a checkmark for the little guy.

You Better Hit Your Target

Dating back to 2019, Pro Football Reference has tracked a pass accuracy stat for all 32 NFL teams called on-target percentage, which measures the rate of a team’s tosses that are on-target, excluding spikes and throwaways. That means that the stat can provide insight into eight of the nine major upsets featured in this article.

Only the 2020-21 Browns’ upset of the Steelers and the 2019-20 Vikings’ upset of the Saints do not fit the mold. In every other instance of a major upset in the last few NFL Playoffs, the underdog beat the favorite in on-target percentage during the regular season, often by a good deal.

In six of the eight major upsets since 2019, the victorious underdog had a better on-target percentage than the crestfallen favorites in the regular season, and in the one instance where the stat is not available, the 2018-19 Eagles bested the 2018-19 Bears in bad pass percentage (13.2 percent to 18.0 percent).

The 2022-23 Bengals, 2021-22 Bengals, and 2021-22 49ers were among the best in the league in their respective seasons in on-target percentage and bad pass percentage. The 2019-20 Titans’ mark of 77.4 percent of passes being on-target was better than the Patriots (73.1 percent) and Ravens (75.6 percent) that season. Tennessee threw fewer bad balls, too.

This does not mean that the pass was equally instrumental in each of these upsets as they played out; the pass held a different role in each of the games. But this strikes me too strongly to be a mere coincidence. I think there is something here, and it stands to reason that there would be.

Football is a team sport. You need everyone to have success, especially at the level required in the NFL Playoffs. But one position rises above the rest, in attention and importance: quarterback.

The NFL is a passing league. Those that dominate aerially are often the most victorious.

The margins in this league are slim, and that’s a truism in the regular season, let alone the playoffs when less than half of the league is allowed entrance. In a single-elimination tournament, capitalizing on the opportunities offered to your offense is crucial. Hit your target, and you have a chance. Accuracy is everything.

For you curious folks back at home, the Cowboys, Lions, Chiefs, Dolphins, and Eagles, round out the top five in the league in on-target percentage, in that order, with just one week of football remaining in the regular season. The teams likely to be seeded lower but that still may qualify for the postseason are the Vikings (sixth at 78.8 percent), the Saints (seventh at 78.7 percent), and the Bills (ninth at 77.5 percent).