Do NFL Referees Unfairly Favor the Kansas City Chiefs?
Using statistics to clear the air once and for all!
Background
In the Divisional NFL playoff game on Saturday January 18, 2025 the Houston Texans out rushed the Kansas City Chiefs 149 yards to 50, out passed them 187 yards to 162, was more efficient on third down, 10 for 17 (59%) vs 4 for 11 (36%), had one less turnover (1 fumble vs 2) and won the time of possession 33:26 to 26:34. If you were just to look at these stats it would be hard to believe that the Texans lost 14 to 23. However, one stat that stood out was the Texans were penalized 8 times for 82 yards while the Chiefs just 4 times for 29 yards. This included two very questionable roughing the passer penalties that Mahomes always seems to generate. This of course led to a ton of discussions and hilarious memes suggesting that the Chiefs get preferential favor by the referees, but is this true? In this article I will use classical statistics to determine if there’s any truth behind these claims.
Hypothesis
My hypothesis is that since Taylor Swift started dating Travis Kelce and attending his games (beginning Week 3 of the 2023 season) the NFL has had a vested interest in making sure the Chiefs play as many games as possible. This is because with Swift’s assistance, the NFL attained its highest regular-season female viewership since it started collecting that data in 2000. The NFL’s viewership experienced a 53% spike among teenage girls, a 24% increase among women aged 18–24, and a 34% rise among women aged 35 and above. The NFL is a business and getting more women and girls interested in football, especially at a young age is great for long term revenue.
Data
I will look at penalty data collected from here starting when Taylor Swift attended her first Chiefs game during Week 3 of the 2023 season to the Conference Playoff round of the 2024 season to determine if the Kansas City Chiefs receive a significantly higher number of penalties and penalty yards than their opponents, indicating unfair treatment.
Data Visualization and Penalty Comparison
From Week 3 of the 2023 season to the Conference Playoff round of the 2024 season (38 games) the Chiefs recorded 200 penalties against them and their opponents recorded 215. This equates to the Chiefs receiving 5.263 penalties per game while their opponents received 5.658. From these results we can see the Chiefs did receive fewer penalties per game, but only 0.395 penalties per game fewer, not a statistically significant difference (p-value = 0.201).
So the Chiefs did NOT receive significantly fewer penalties over the 38 games between Week 3 of the 2023 season to the Conference Playoff round of the 2024 season, but did they receive significantly fewer penalty yards?
Over these 38 games the Chiefs received 1,750 total penalty yards while their opponents received 1,735 total penalty yards. This equates to the Chiefs receiving 46.053 penalty yards per game while their opponents actually received 0.395 penalty yards per game less at 45.658, also not a statistically significant difference (p-value = 0.470).
So there you have it, yes the Chiefs received a mere 0.395 fewer penalties per game from Week 3 of the 2023 season to the Conference Playoff round of the 2024 season (38 games) but actually recorded 0.395 more penalty yards per game than their opponents indicating the refs are not being bias towards the Chiefs right?
Well maybe not.
If we’re going full tin hat conspiracy theory on this we have to think like the NFL would think. It would be impossible for the refs to be so bias that you take a complete garbage fire of a team and make so many calls that they get into the playoffs. But what if a good team like the Chiefs just needs a little bit more help to get to play as many games as possible, aka make it to the Superbowl? Well that would mean you would just have to be bias during the time of the year where games mean the most, Weeks 15 to the Conference Championship games. Games before week 15 would be to hard to influence for so long and by the time the Superbowl comes around the Chiefs (and Taylor) would have already been in as many games as possible.
With this theory in mind I think we need to document our methodology.
Methodology
I will compare the number of penalties and penalty yards per game from Weeks 1 to 14 plus the Superbowl to what I’m calling the crunch time which is Weeks 15 to the Conference Championship to see if the Chiefs receive fewer penalties and penalty yards in the crunch times where games matter more.
I will compare this data in three different aspects to get a complete story:
- Do the KC Chiefs receive fewer penalties and penalty yards in the crunch time than the rest of the season?
- Do the Chiefs’ opponents receive more penalties and penalty yards in the crunch time than the rest of the season?
- Do the Chiefs receive statistically significantly fewer penalties and penalty yards than their opponents in the crunch time with an emphasis on the playoff non-Superbowl games where the competition is toughest.
Keep in mind our original data is Week 3 of the 2023 season to the Conference Playoff round of the 2024 season (38 games) and I will continue using this data for our updated methodology.
1. Kansas City Chiefs Results
First let’s compare the number of penalties and penalty yards for the Chiefs in Weeks 1 to 14 plus the Superbowl to the crunch time (Weeks 15 to the Conference Championship).
For the 25 games the Chiefs played in Weeks 1 to 14 plus one Superbowl they averaged 150 penalties or 6 penalties per game. However during 13 games in crunch time, Weeks 15 to the Conference Championship, the Chiefs had 50 penalties or 3.85 penalties per game. This equates to a difference of 2.15 penalties per game less during crunch time (Weeks 15 to the Conference Championship), which is a statistically significantly smaller number indicating the refs may be unfairly bias for the Chiefs when the games matter most:
We’ve shown the Chiefs receive significantly fewer penalties during crunch time, but do they receive significantly fewer penalty yards as well?
For the 25 games the Chiefs played in Weeks 1 to 14 plus one Superbowl they averaged 1,300 penalty yards or 52 penalty yards per game. However during 13 games in crunch time, Weeks 15 to the Conference Championship, the Chiefs had 450 penalty yards or 34.62 penalty yards per game. This equates to a difference of 17.38 fewer penalty yards per game during crunch time (Weeks 15 to the Conference Championship), which is a statistically significantly smaller number, again indicating the refs may be unfairly bias for the Chiefs when the games matter most:
We have just proven the Chiefs receive statistically significantly fewer penalties per game and penalty yards per game in crunch time (Weeks 15 to the Conference Championship) compared to Weeks 1 to 14 plus the Superbowl.
2. Chief’s Opponents' Results
Above we’ve proven the Chiefs receive statistically significantly fewer penalties and penalty yards in crunch time (Weeks 15 to the Conference Championship) compared to Weeks 1 to 14 plus the Superbowl. We now must determine is:
- Are the Chiefs’ opponents also receiving significantly fewer penalties and penalty yards in crunch time? This would indicate there is no bias, rather the referees simply call fewer penalties in crunch time than the rest of the season.
- OR do the Chiefs’ opponents NOT receive significantly more or less penalties and penalty yards indicating that the referees favor KC by simply calling fewer penalties on them in the crunch time and calling the same amount for their opponent.
- OR do the Chief’s opponents receive significantly more penalties indicating that the referees favor KC by both calling fewer penalties on them and more on their opponents in the crunch time.
For the 25 games the Chiefs’ Opponents played in Weeks 1 to 14 plus one Superbowl they received 146 penalties or 5.84 penalties per game. However during 13 games in crunch time, Weeks 15 to the Conference Championship, the Chiefs’ opponents had 69 penalties or 5.31 penalties per game. This equates to a difference of only 0.53 penalties per game less during crunch time (Weeks 15 to the Conference Championship), which is NOT a statistically significantly smaller number. In other words, unlike the Chiefs who receive statistically significantly fewer penalties during crunch time, their opponents DO NOT.
So the Chiefs’ opponents do not receive a different number of penalties in crunch time than the rest of season, but do they receive a different number of penalty yards?
For the 25 games the Chiefs’ opponents played in Weeks 1 to 14 plus one Superbowl they averaged 1,174 penalty yards or 46.96 penalty yards per game. However during 13 games in crunch time, Weeks 15 to the Conference Championship, the Chiefs’ opponents had 561 penalty yards or 43.15 penalty yards per game. This equates to a difference of 3.81 fewer penalty yards per game during crunch time (Weeks 15 to the Conference Championship), which is NOT a statistically significantly smaller number:
This section demonstrates that unlike the Chiefs who had statistically significantly fewer penalties and penalty yards during crunch time, their opponents did NOT receive this same benefit. The data shows no statistically significant change in the number of penalties and penalty yards for the Chiefs’ opponents between crunch time (Weeks 15 to the Conference Championship) compared to Weeks 1 to 14 plus the Superbowl.
3. Comparison of Penalties During Crunch Time
In the above sections we have proven that the Kansas City Chiefs receive statistically significantly fewer penalties and penalty yards in crunch time (Weeks 15 to the Conference Championship) compared to Weeks 1 to 14 plus the Superbowl and their opponents did not. Now we have to test, in the 13 games since 2023 the Kansas City Chiefs have played in Weeks 15 to the Conference Championship, do they receive significantly fewer penalties per game and penalty yards per game than their opponents?
In the 13 games played during crunch time the Chiefs recorded 50 penalties which equates to 3.85 penalties per game and their opponents recorded 69 which equates to 5.31 penalties per game. This results in the KC Chiefs receiving, on average, 1.46 fewer penalties per game than their opponents during crunch time which is statistically significantly fewer:
Let’s now look at Penalty Yards per Game:
In the 13 games played during crunch time the Chiefs recorded 450 penalty yards which equates to 34.62 penalty yards per game and their opponents recorded 561 which equates to 43.15 penalty yards per game. This was not statistically significant with a p-value = 0.218, however our small sample size is definitely a reason for this. Clearly, the Chiefs are receiving fewer penalties and fewer penalty yards than their opponents in crunch time (Weeks 15 to the Conference Championship), especially during the playoffs.
Playoffs non-Superbowl
In the five non-Superbowl playoff games played, the Chiefs recorded 19 penalties which equates to 3.8 penalties per game and their opponents recorded 35 which equates to 7 penalties per game. This is a statistically significant difference with a p-value = 0.004:
Again, let’s next look at penalty yards per game in the five non-Superbowl playoff games:
In the five non-Superbowl playoff games played the Chiefs recorded 140 penalty yards which equates to 28 penalty yards per game and their opponents recorded 315 which equates to 63 penalty yards per game. This is a statistically significant difference with a p-value = 0.013.
These tests show that Kansas City are penalized statistically significantly less and receive statistically significantly less penalty yards in the non-Superbowl playoff games than they are compared to the rest of the season and compared to their opponents in these games.
Conclusions
I truly believe that the NFL referees are unfairly favoring the Kansas City Chiefs by penalizing them less during the crunch time of the NFL season (Weeks 15 to the Conference Championship).
In this analysis I have proven that the Chiefs receive statistically significantly fewer penalties (3.85 vs 6) and fewer penalty yards per game (34.62 vs 52) in the crunch time between Weeks 15 to the Conference Championship game than they did in Weeks 1 to 14 plus one Superbowl.
This same trend was not seen for the Chiefs’ opponents who did not receive statistically significantly fewer penalties (5.31 vs 5.84) or fewer penalty yards per game (43.15 vs 46.96) in the crunch time between Weeks 15 to the Conference Championship game than they did in Weeks 1 to 14 plus one Superbowl.
In addition the Chiefs received statistically significantly fewer penalties per game (3.85 to 5.31) and fewer penalty yards per game (34.62 to 43.15) than their opponents in the crunch time between Weeks 15 to the Conference Championship game. This difference is even more exaggerated in the Wildcard, Divisional and Conference playoff games (n = 5) where the Chiefs received statistically significantly fewer penalties (3.8 vs 7) and statistically significantly fewer penalty yards per game (28 vs 63).
In terms of motive, the NFL has a huge interest on getting the Chiefs to play as many games as possible. As mentioned earlier, since Taylor Swift started to date Travis Kelce, female NFL viewership has increased significantly. With Kelce getting older and looking close to retirement, plus T Swift’s dating history, the NFL know this cash cow won’t last forever and now is the time to get as much revenue and potential long term new fans as possible before it’s over. As the season goes on and games are becoming more important NFL referees are helping the Kansas City Chiefs get to the Superbowl, especially during the playoffs.
