KC Chiefs Patrick Mahomes #15 is stopped by LA Chargers' Tarheeb Still #29 and Troy Dye #43 during an NFL football game at SoFi Stadium, Aug. 17, 2024, in Inglewood, Calif. (Credit: Ringo Chiu on Shutterstock)
In A Nutshell
- A 2025 academic study analyzed 13,136 NFL defensive penalties from 2015–2023 using detailed play-by-play data.
- During the Mahomes era (2018–2023), postseason calls against Chiefs opponents averaged 2.36 more yards and were 23% more likely to result in first downs than league norms.
- The same team received less favorable calls in the regular season—a 31-point swing that the authors describe as a 388% reversal from baseline.
- The advantage concentrated on third and fourth downs and in strong scoring situations, when penalties most affect outcomes.
- Officials who had previously worked Chiefs playoff games were the only ones showing this postseason effect; new crews did not.
- Researchers link the pattern’s timing to Kansas City’s rise as the NFL’s biggest TV draw but stress that the findings show correlation, not proof of intent or corruption.
EL PASO, Texas — Patrick Mahomes takes the field, and suddenly the rulebook appears to shift in Kansas City’s favor. At least, that’s what the numbers suggest.
A new academic study analyzing over 13,000 defensive penalties from 2015 to 2023 reveals a notable pattern: during the postseason, referees call penalties that benefit the Mahomes-era Kansas City Chiefs at rates dramatically higher than both the regular season and other NFL dynasties. The shift coincides almost perfectly with the team’s emergence as the league’s biggest ratings draw during a period when the NFL desperately needed one.
The research, conducted by Spencer Barnes from the University of Texas at El Paso, Brandon Mendez from the University of South Carolina, and independent researcher Ted Dischman, found that defensive penalties against the Chiefs offense in playoff games yield on average 2.36 more yards, are on average 23 percentage points more likely to result in a first down, and are on average 28 percentage points more likely to involve subjective referee judgment compared to the rest of the league.
Here’s the twist: during the regular season, the Chiefs actually receive fewer favorable penalty calls than average. Penalties against their opponents result in on average 2.02 fewer yards and are on average 8 percentage points less likely to produce first downs compared to other teams. The 31-percentage-point swing in first-down penalties from regular season to playoffs represents a 388% reversal from Kansas City’s regular-season baseline.
When Ratings Tanked, Mahomes Rose
The timing matters. Patrick Mahomes became the Chiefs’ starting quarterback in 2018, right as the NFL was climbing out of a viewership crisis. From 2015 to 2017, TV ratings had plummeted amid political controversies surrounding player protests during the national anthem. Average ratings dropped from 12.77 in 2015 to 9.92 in 2017, a significant decline for a league where television broadcast rights constitute the largest revenue source.
Enter Mahomes. After he took over, Chiefs games began consistently outperforming the rest of the league. The researchers manually compiled TV data from Sports Media Watch and found that following Mahomes’ arrival, Kansas City games attracted an additional 3.87 million viewers on average compared to other NFL broadcasts. That’s a 19% bump in ratings, translating to enormous sums in a league where television contracts are the primary revenue source. The NFL generated approximately $23 billion in 2024, comparable to Fortune 500 companies like 3M and Waste Management.
The penalty advantages aren’t trivial either. The researchers calculated that Kansas City’s 13 postseason appearances since 2018 featured 78 total penalties that, under their estimates, translated to 16.2 net first downs and 198.5 net penalty yards favoring the Chiefs. In a league where the average playoff margin of victory from 2018-2023 was just 9.23 points, these aren’t abstract statistical quirks. Kansas City’s average margin of victory in AFC Championship games during this period was only 5.2 points, and their four Super Bowl appearances averaged a razor-thin 0.5-point margin.
The Calls Come When They Count Most
The favorable treatment isn’t random. It appears precisely when it matters most for keeping drives alive and points on the board. When researchers analyzed penalties by game situation, they found refs were significantly more likely to call penalties benefiting Kansas City on third or fourth down, the exact moments when a flag can mean the difference between punting and scoring. In postseason games, penalties on high-leverage downs resulted in on average 3.76 additional yards for the Chiefs, were on average 19 percentage points more likely to produce first downs, and were on average 26 percentage points more likely to be subjective calls requiring referee discretion.
Similar patterns emerged when examining expected points added (EPA), a metric measuring how much a play increases a team’s likelihood of scoring. In the playoffs, penalties favoring the Chiefs occurred disproportionately when Kansas City’s offense was already in strong scoring position, further tilting the field.
Compare this to Tom Brady’s New England Patriots dynasty from 2015-2019. The researchers found no comparable postseason officiating advantage for New England despite their similar dominance and star power. The Brady-era Patriots received roughly the same penalty treatment in regular season and playoffs. Neither did other recent contenders like the Philadelphia Eagles, Los Angeles Rams, or San Francisco 49ers show similar patterns.
Even the pre-Mahomes Chiefs, led by Alex Smith under the same head coach Andy Reid from 2015-2017, received no postseason boost. That rules out coaching style or team strategy as explanations. Something changed specifically with the Mahomes era.
The Referee Rotation Raises Eyebrows
Perhaps the most eyebrow-raising finding involves which referees are calling these favorable penalties. The researchers tracked officiating crews and discovered that the postseason advantage for Kansas City was driven entirely by referees who had worked Chiefs playoff games in prior seasons. Officials with previous Chiefs playoff exposure called games significantly more favorably for Kansas City in subsequent contests. Referees without such experience showed no bias.
The NFL assigns its highest-graded officials to work the postseason. These assignments carry financial bonuses and reputational prestige. By repeatedly assigning the same pool of referees who demonstrate a history of favorable Chiefs calls back to Kansas City playoff games, the league may be amplifying the team’s postseason advantages, whether intentionally or not.
The researchers acknowledge they cannot establish causation or prove explicit corruption. Their study, published in The Financial Review, shows correlation and patterns, not smoking guns. The researchers note this pattern is consistent with, but not proof of, incentive alignment between officials and league priorities. The NFL’s grading criteria for officials are opaque and non-public, making it impossible to know whether “performance” evaluations might implicitly reward outcomes aligned with league financial interests.
Still, the numbers fuel ongoing debates among fans about officiating consistency. During Super Bowl LIX, controversial calls prompted Dave Portnoy, founder of Barstool Sports, to immediately characterize the officiating as “rigged” on social media. Whether rigged or not, the systematic differences in how rules are enforced for the NFL’s most valuable television property highlight questions about professional sports integrity when billions of dollars are at stake.
The researchers don’t claim to know why these patterns exist, only that they do. Other factors like broader league interests in protecting star players, maintaining competitive narratives, or enhancing entertainment value could contribute. The post-pandemic surge in live sports viewership and the NFL’s massive new broadcasting deal in 2021 complicate any simple financial explanation.
What’s clear is this: if Patrick Mahomes and the Chiefs take the field in January, the flags fly differently than they do in September. And those differences, whether by design or happenstance, just happen to benefit the team that keeps America watching.
Paper Summary
Methodology
The researchers analyzed play-by-play data from 13,136 defensive penalties across all NFL games from 2015 to 2023, obtained from the open-source nflfastR project. They employed fixed-effects panel regression models to compare penalty outcomes for the Mahomes-era Kansas City Chiefs (2018-2023) and Brady-era New England Patriots (2015-2019) across regular season and postseason games. The models controlled for contextual factors including season-by-week, down, yards to go, defensive team, and home team, isolating the effect of team status on three penalty-related outcomes: total yards, whether the penalty resulted in a first down, and whether the penalty was classified as subjective (requiring referee discretion such as pass interference, defensive holding, or roughing the passer). The researchers also manually compiled TV ratings and viewership data from Sports Media Watch covering 1,034 nationally televised games from 2015-2023 to test whether Chiefs games attracted higher audiences during the Mahomes era. Additional analyses examined penalty timing by expected points added (EPA) and down-to-go situations, and tracked individual referee assignments to determine if prior Chiefs playoff experience correlated with officiating behavior.
Results
The study found that Mahomes-era Chiefs receive significantly more favorable penalty outcomes in postseason games compared to both their regular season performance and other dynasty teams. During the playoffs, defensive penalties against Kansas City’s offense yield on average 2.36 more yards, are on average 23 percentage points more likely to result in first downs, and are on average 28 percentage points more likely to be subjective calls compared to the rest of the NFL. During the regular season, the Chiefs actually receive less favorable treatment with on average 2.02 fewer penalty yards, 8 percentage points fewer first-down penalties, and 7 percentage points fewer subjective calls. No comparable postseason officiating differences were found for the Brady-era Patriots or other recent contenders including the Eagles, Rams, and 49ers. The favorable treatment intensifies in high-leverage situations, with significantly more beneficial calls on third or fourth downs and in high EPA moments. Regarding the financial mechanism, Chiefs games attracted on average 3.87 million additional viewers and a 1.98-point higher TV rating following Mahomes’ arrival in 2018 compared to other NFL games. The postseason Chiefs advantage was driven entirely by officiating crews that included at least one referee who had worked a Chiefs playoff game in the prior season.
Limitations
The study does not establish causation and explicitly notes the findings show correlation rather than proof of intentional bias or corruption. The analysis lacks a valid natural experiment to explore causal mechanisms, limiting conclusions to correlative estimates. Second, the TV viewership data covers only nationally televised games, excluding regionally broadcast contests that represent a substantial portion of regular season matchups, which introduces selection bias toward higher-profile games. Third, the study period (2015-2023) coincides with multiple confounding factors including the NFL’s recovery from politically charged viewership declines (2015-2017), post-pandemic surges in live sports consumption, and the 2021 broadcasting rights deal, making it difficult to isolate financial incentives specific to Chiefs success. Fourth, the researchers cannot observe or measure the NFL’s internal referee grading criteria, which are opaque and non-public, preventing direct assessment of whether performance evaluations explicitly reward outcomes favoring high-value teams. Fifth, other plausible mechanisms beyond direct financial incentives, such as unconscious bias toward star players, league interests in competitive narratives, or officials’ desire to avoid controversy by deferring to offensive stars, could explain the patterns but cannot be definitively ruled in or out. Finally, the study cannot determine whether the observed patterns reflect top-down institutional design, emergent behavior from aligned incentives, or some combination of both.
Funding and Disclosures
The paper does not report any external funding sources or financial conflicts of interest. The authors are affiliated with academic institutions (University of Texas at El Paso and University of South Carolina) and one independent researcher. No disclosures regarding relationships with sports betting companies, media organizations, or professional sports leagues are mentioned.
Publication Details
Barnes, S., Mendez, B., & Dischman, T. (2025). “Under (financial) pressure,” The Financial Review, August 28, 2025. University of Texas at El Paso; University of South Carolina. DOI: 10.1111/fire.70020
