User PolarVortices on the Huskers sub reddit went into some depth regarding penalties in the B1G for us. Below is copy pasted from him post last night. Kudos to him for putting this together.
*** VERY LONG ***
As most people are aware, during the Minnesota game a stat was posted by the broadcasting team. It indicated that the offensive holding call against Minnesota during a passing play (accepted penalty) was the first one Nebraska had against an opponent in 21 conference games dating back to 2015. This was shocking for a few reasons which I think were covered quite well by u/themrincredible from a post a few days ago and is worth reading if you get the chance:
One of the takeaways from this post, among a few podcasts I also listen to on the sub suggested that perhaps Nebraska was facing bias from the refereeing within the B1G. As I dwelled upon the thought, I figured I would put together some basic stats and look at Nebraska’s penalty history since joining the B1G. As I dug deeper I found myself wanting to know more and compare more however, at the current time the stats are still at the descriptive level.
Before we jump into what everything looks like we first need to acknowledge a few items about some assumptions we will make for the sake of analysis.
Assumption 1: Teams will be sloppier and penalized more frequently at the beginning of the season than at the end. Teams should improve over the course of the season which ties into to assumption 2. I tested this theory using a Pearson’s R correlation and have included charts below:
The Pearson’s R correlation for Penalties Per Game and Month is R2 = -0.688, p < .01 which indicates a significant and strong negative correlation between penalties and time ie refutes the null hypothesis that there’s no relationship between penalties per game and time.
The Pearson’s R is similar for Pen. Yards per game and Month at R2 = -0.618, p < .01 suggesting a similarly strong and negative correlation. Together these correlations should help to support the notion that as teams get further into the season their penalties should decrease as a whole despite some anomalies seen in CCG and Bowl games.
Another interesting observation from the charts is that penalty yards per game has been consistently higher from 2014 onwards.
Assumption 2: Because of the B1G schedule OOC games are usually played at the start of the season so most teams should have improved before they play another B1G school with B1G refs. This means that we should see a change between OOC penalties and within conference penalties. If bias is present we should see penalties for Nebraska increase rather than decrease especially given the first assumption (that teams improve over the course of the season). An improvement in play however, may offset an increase in calls from the refs meaning the observed result is almost no change between OOC and within Conference penalties for Nebraska.
To determine if ‘bias’ is present then we need to test a few things with these assumptions in mind. First, we will examine Nebraska’s general trend for penalties within the B1G in comparison to the average over the 8 years. Next, we will compare those to opposition penalties called when they played Nebraska. This will establish whether Nebraska seems to be above and beyond being treated more unfairly by the refs by both being punished more severely and having opponents being given the benefit of the doubt.
The second thing we will examine will help to control for counter-arguments against any conclusions we may draw from the first analysis. People may say Nebraska was just a sloppy team and being above the average doesn’t prove anything which is fair, however, we will compare the OOC penalties for Nebraska for each year to the within conference penalties called by the B1G establishing whether or not that argument is true while keeping assumption 1 and 2 in mind. If Nebraska’s penalty yards don’t drop from OOC to within Conference and instead sometimes increase, it may support any conclusions regarding bias from the first analysis. Again, this will be done using both Nebraska’s penalty yards and their opponent’s penalties committed against them.
So what does Nebraska’s penalties look like over the same time frame?
In the entirety of Nebraska’s time within the B1G they have never had a year at or below the B1G average for penalties. 2014 the differential was 2.14 yards per game and in 2016 it was as low as 1.81 yards per game but that’s as close as it gets. 2018 of course has been a bit of an anomaly at 27.49 yards per game over the average but in 2011, 2012 and 2017 those numbers were still between 11.5 to 13 yards per game over the B1G average. This appears to support the idea that Nebraska may be experiencing some bias especially in comparison to the B1G average for within conference games. The total average over 8 years suggests Nebraska experiences 9.97 more penalty yards per game than the B1G average for within conference games. The next chart compares Nebraska to the entirety of the FBS.
Nebraska’s penalties in 2013-2016 were all below the FBS average suggesting that they weren’t some sort of sloppy team that should have seen more penalties and yet we were still above the B1G average for all of those years. Unpacking this a bit further we can see that the trends are much better for penalties called against opponents that Nebraska plays.
In 2011, 2012 and 2015 B1G opponents versus Nebraska had 3.4, 2.5 and 1.9 penalty yards per game more than average for the B1G. In 2013, 2014, and 2016-2018 Nebraska’s opposition were well below the average for the B1G. For the 8 years Nebraska has been in the B1G opponents are called for 2.33 less penalty yards per game on average.
Okay so far, we’ve established some telling trends but only in comparison to the B1G averages, lets unpack this a bit and examine other teams:
Over the 8 years Nebraska has been in the B1G they have the largest penalty differential observed where they average almost 10 yards per game more than the B1G. Ohio State is next closest at 7.69 all the way down to Iowa who experiences 11.37 less yards per game in penalties compared to the B1G average over the course of 8 years. This chart also hopefully dispels any myths regarding the notion that better teams with more skillful players have less penalties as you can see that teams seem to be distributed evenly. The charts for these data are below:
As you can see Iowa seems to either have the most disciplined team in the B1G year to year or perhaps there's something more going on. 2015 and 2016 were the only two years they were above the B1G average and those differences were minor. No other team than Nebraska has had the same run of never having a penalty year below the B1G average in the last 8 years. Northwestern and Penn St are consistently under the average despite Iowa having the largest overall differential.
Now lets combine these results with the second penalty metric examining opposition penalties called against teams.
This table seems to indicate that while Nebraska’s opponents enjoy 2.33 less penalty yards per game than the B1G average that result is in the middle of the pack. Wisconsin and Minnesota experience some of the worst differentials with their opponents being called for quite a few less penalty yards per game while Indiana and Penn St experience the opposite. Again these results should also dispel the notion that ranking or skill is playing into the penalty calls as you can see the traditionally ranked teams are dispersed within the table.
Tables for this are below and there are again some interesting results: Did 2016 Purdue feel extra spooky? Their B1G opponents averaged almost 30 yards more in penalties per game over the mean and 2018 isn’t looking much better. Wisconsin is having a tough time this season with two in conference losses and their opponents are averaging 25.61 less penalty yards per game when they play and that includes a game against the worst offender in the league… Nebraska. Maryland so far this season in the B1G seems to be getting absolutely hosed, with their opposition experiencing almost 40 less yards per game on average than the B1G.
For the sake of transparency and consistency here’s the same over/under table for opp. Penalty yards.
So, while Nebraska doesn’t experience the worst in this category they are still in the bottom 3. Some teams in this chart are also in similar positions to the penalty stat above with Iowa and Penn St. seemingly in an advantageous position. Penn St. has 7 years below the average penalty stat and 7 years where their opponents are above the average penalties for the B1G. Iowa is similar with 6 years below and 6 years above for their opponents. Indiana on the other hand experiences some of the most benefits from calls against their opposition however, they also are well above the average for calls against them perhaps offsetting some of the damage.
Moving forward we can examine the net differential for penalty yards within the B1G, so, lets combine penalty yards and the opposition penalty yards to determine who has the best and worst net differentials for penalty yards in the B1G:
Recognize that familiar face? Yes, it’s Nebraska at the top again, where we experience a differential of 12.31 yards per game. We are called for more penalties than anyone in the B1G and combined with our opponent’s penalties makes us the overall leader. Ohio St and Mich St both also experience some of this bias while Wisconsin’s differential mostly offsetting. If it feels a bit biased when you play Northwestern, Penn St or Iowa you’re probably not wrong with those three teams each experiencing a 10.72, 12.67 and 14.72 yard penalty differential against B1G opponents.
Now that we’ve established Nebraska’s position within the B1G let’s address the first complaint that people will make, “Nebraska is just a sloppy team saying they are above average doesn’t prove anything.” It’s a valid point that we can hopefully address with the next set of analysis. Let’s revisit the first assumption we’ve made and hopefully shown earlier, as the season progresses teams improve and seem to experience less penalties overall and less yards per game in penalties. Even if Nebraska is a sloppy team that experiences more penalties and their opponents aren’t called for a lot of penalties they should still see improvement if the first assumption is true.
The second assumption addresses this improvement metric by comparing calls made outside of the B1G conference with those made within. If Nebraska above all the other B1G teams sees the worst amount of improvement moving from OOC to within Conference I would argue that it’s difficult not to see the presence of at least some bias. With that being said, let’s dive on in:
For 2011, Nebraska’s rank for all of the FBS was 22nd in yards per game called against their opponents when we look at just within the conference their place fell to 55th with opponents being called for 7.4 less yards per game within the B1G over the OOC games. So the argument that they were a sloppy team (ranked 22nd) seems like an unfair argument to make and yet when we only look at the B1G games they saw huge reductions in calls against their opponents. 2011 saw Nebraska play a mix of some of the worst culprits for penalties Mich St was 80th overall and 92 within the conference differential of 15 penalty yards per game over the average as well as teams like Wisconsin ranked 16th and 11th with a differential of -12. So I would suggest that the argument about Nebraska only playing disciplined conference opponents doesn’t hold up.
Spoiler alert! This trend holds for all 8 years that Nebraska has been within the B1G, we have never seen a single season where calls against our opponents within the B1G improve.
Overall the trends look like this for all teams:
Nebraska fell 17.5 ranks on average in the FBS when we compare all games to within conference games while teams like Michigan and Iowa moved up places over the 8 years. The average for the B1G was -2.32 with a SD of 6.36, although the sample size is small it’s a big leap to fall so far so often for Nebraska. Over 8 years across the OOC and within Conference games our opponents consistently get called for 5.78 less yards per game as we move to play teams within the B1G. Maryland is the only team that’s even close but still saw at least three years where they improved in position. Interestingly the B1G generally sees little improvement in opposition penalty yards per game moving within conference with Iowa and Purdue being the only teams that see benefits to moving into Conference play.
But maybe Nebraska always just starts highly ranked because our OOC schedule is weak and those teams get called for a lot of penalties so moving into Conference play is always going offset that. Well let’s examine that as well:
Whether it was years where we started 22nd or years that we started 109th we always saw a rank reduction and a penalty yards per game reduction moving into the B1G. Now let’s move into whether this holds up when we examine Nebraska’s penalties instead of just their opposition’s calls.
The results seem to indicate that Nebraska experiences improvement moving from OOC to within the Conference about 8.5 ranks of improvement and 1.99 less yards per game in penalties moving into the B1G from OOC. Indiana sees the most benefit while Wisconsin seems to experience the least indicating more severe officiating within conference. What is telling to me about this stat is that it shows Nebraska does improve their sloppiness as a team leading to a reduction in penalty yards and yet somehow every single season our opponents improve at a better rate. We reduce our penalties game to game over the course of a season and yet the other B1G teams improve more than we do when we play against them which leads to us never having a single season of improvement for opposition penalties called when we play them. Let’s finally compare the net yards as we did with the means for the B1G to see what it looks like when you combine calls against your opponents when you play them and calls against your team.
Overall Nebraska still ranks second to last in this category experiencing a net reduction in benefit moving into B1G play from OOC. In fact, 8 of the 14 teams experience more severe punishment moving into the B1G despite the metric provided for assumption 1 suggesting that teams really do improve as the season progresses.
tldr; Almost 3000 words later let’s recap what we’ve found: Nebraska has the worst net differential in yards within the B1G combining both calls against their opponents when they play and calls against Nebraska over the 8 years. The argument that over the last 8 years Nebraska has just been a sloppy team is unfounded, some years we are high, some years we are low.
Teams generally improve over the course of the season reducing their penalty yardage and overall penalties. In spite of this, Nebraska is second to last in the B1G moving from OOC to within Conference play with a net differential of 3.79 yards per game. Combining the results of the OOC to within Conference and the Overall B1G stats the net yardages look like this:
Nebraska sees the 2nd least benefit moving into conference play, and the worst within conference benefit in the B1G.
To answer the question of whether Nebraska sees bias in officiating within the B1G I would suggest that it is hard to argue against this premise given these results. There are of course limitations to this analysis such as the non-inclusion of accepted versus not accepted penalties however, I’m not sure they would change the results all that much. I’ve tried to control for a lot of the possible counter arguments against the notion of at least some bias in officiating while still recognizing that 8 years of data isn’t necessarily large enough to draw generalizations and conclusions from. These results could all be within the margin of error given the relatively low n.
If anyone has any suggestions to improve on any of this don’t hesitate to comment.
******
Said that he worked about 20 hours on this. Kudos to this guy for his work on this.
*** VERY LONG ***
As most people are aware, during the Minnesota game a stat was posted by the broadcasting team. It indicated that the offensive holding call against Minnesota during a passing play (accepted penalty) was the first one Nebraska had against an opponent in 21 conference games dating back to 2015. This was shocking for a few reasons which I think were covered quite well by u/themrincredible from a post a few days ago and is worth reading if you get the chance:
One of the takeaways from this post, among a few podcasts I also listen to on the sub suggested that perhaps Nebraska was facing bias from the refereeing within the B1G. As I dwelled upon the thought, I figured I would put together some basic stats and look at Nebraska’s penalty history since joining the B1G. As I dug deeper I found myself wanting to know more and compare more however, at the current time the stats are still at the descriptive level.
Before we jump into what everything looks like we first need to acknowledge a few items about some assumptions we will make for the sake of analysis.
Assumption 1: Teams will be sloppier and penalized more frequently at the beginning of the season than at the end. Teams should improve over the course of the season which ties into to assumption 2. I tested this theory using a Pearson’s R correlation and have included charts below:
The Pearson’s R correlation for Penalties Per Game and Month is R2 = -0.688, p < .01 which indicates a significant and strong negative correlation between penalties and time ie refutes the null hypothesis that there’s no relationship between penalties per game and time.
The Pearson’s R is similar for Pen. Yards per game and Month at R2 = -0.618, p < .01 suggesting a similarly strong and negative correlation. Together these correlations should help to support the notion that as teams get further into the season their penalties should decrease as a whole despite some anomalies seen in CCG and Bowl games.
Another interesting observation from the charts is that penalty yards per game has been consistently higher from 2014 onwards.
Assumption 2: Because of the B1G schedule OOC games are usually played at the start of the season so most teams should have improved before they play another B1G school with B1G refs. This means that we should see a change between OOC penalties and within conference penalties. If bias is present we should see penalties for Nebraska increase rather than decrease especially given the first assumption (that teams improve over the course of the season). An improvement in play however, may offset an increase in calls from the refs meaning the observed result is almost no change between OOC and within Conference penalties for Nebraska.
To determine if ‘bias’ is present then we need to test a few things with these assumptions in mind. First, we will examine Nebraska’s general trend for penalties within the B1G in comparison to the average over the 8 years. Next, we will compare those to opposition penalties called when they played Nebraska. This will establish whether Nebraska seems to be above and beyond being treated more unfairly by the refs by both being punished more severely and having opponents being given the benefit of the doubt.
The second thing we will examine will help to control for counter-arguments against any conclusions we may draw from the first analysis. People may say Nebraska was just a sloppy team and being above the average doesn’t prove anything which is fair, however, we will compare the OOC penalties for Nebraska for each year to the within conference penalties called by the B1G establishing whether or not that argument is true while keeping assumption 1 and 2 in mind. If Nebraska’s penalty yards don’t drop from OOC to within Conference and instead sometimes increase, it may support any conclusions regarding bias from the first analysis. Again, this will be done using both Nebraska’s penalty yards and their opponent’s penalties committed against them.
So what does Nebraska’s penalties look like over the same time frame?
In the entirety of Nebraska’s time within the B1G they have never had a year at or below the B1G average for penalties. 2014 the differential was 2.14 yards per game and in 2016 it was as low as 1.81 yards per game but that’s as close as it gets. 2018 of course has been a bit of an anomaly at 27.49 yards per game over the average but in 2011, 2012 and 2017 those numbers were still between 11.5 to 13 yards per game over the B1G average. This appears to support the idea that Nebraska may be experiencing some bias especially in comparison to the B1G average for within conference games. The total average over 8 years suggests Nebraska experiences 9.97 more penalty yards per game than the B1G average for within conference games. The next chart compares Nebraska to the entirety of the FBS.
Nebraska’s penalties in 2013-2016 were all below the FBS average suggesting that they weren’t some sort of sloppy team that should have seen more penalties and yet we were still above the B1G average for all of those years. Unpacking this a bit further we can see that the trends are much better for penalties called against opponents that Nebraska plays.
In 2011, 2012 and 2015 B1G opponents versus Nebraska had 3.4, 2.5 and 1.9 penalty yards per game more than average for the B1G. In 2013, 2014, and 2016-2018 Nebraska’s opposition were well below the average for the B1G. For the 8 years Nebraska has been in the B1G opponents are called for 2.33 less penalty yards per game on average.
Okay so far, we’ve established some telling trends but only in comparison to the B1G averages, lets unpack this a bit and examine other teams:
Over the 8 years Nebraska has been in the B1G they have the largest penalty differential observed where they average almost 10 yards per game more than the B1G. Ohio State is next closest at 7.69 all the way down to Iowa who experiences 11.37 less yards per game in penalties compared to the B1G average over the course of 8 years. This chart also hopefully dispels any myths regarding the notion that better teams with more skillful players have less penalties as you can see that teams seem to be distributed evenly. The charts for these data are below:
As you can see Iowa seems to either have the most disciplined team in the B1G year to year or perhaps there's something more going on. 2015 and 2016 were the only two years they were above the B1G average and those differences were minor. No other team than Nebraska has had the same run of never having a penalty year below the B1G average in the last 8 years. Northwestern and Penn St are consistently under the average despite Iowa having the largest overall differential.
Now lets combine these results with the second penalty metric examining opposition penalties called against teams.
This table seems to indicate that while Nebraska’s opponents enjoy 2.33 less penalty yards per game than the B1G average that result is in the middle of the pack. Wisconsin and Minnesota experience some of the worst differentials with their opponents being called for quite a few less penalty yards per game while Indiana and Penn St experience the opposite. Again these results should also dispel the notion that ranking or skill is playing into the penalty calls as you can see the traditionally ranked teams are dispersed within the table.
Tables for this are below and there are again some interesting results: Did 2016 Purdue feel extra spooky? Their B1G opponents averaged almost 30 yards more in penalties per game over the mean and 2018 isn’t looking much better. Wisconsin is having a tough time this season with two in conference losses and their opponents are averaging 25.61 less penalty yards per game when they play and that includes a game against the worst offender in the league… Nebraska. Maryland so far this season in the B1G seems to be getting absolutely hosed, with their opposition experiencing almost 40 less yards per game on average than the B1G.
For the sake of transparency and consistency here’s the same over/under table for opp. Penalty yards.
So, while Nebraska doesn’t experience the worst in this category they are still in the bottom 3. Some teams in this chart are also in similar positions to the penalty stat above with Iowa and Penn St. seemingly in an advantageous position. Penn St. has 7 years below the average penalty stat and 7 years where their opponents are above the average penalties for the B1G. Iowa is similar with 6 years below and 6 years above for their opponents. Indiana on the other hand experiences some of the most benefits from calls against their opposition however, they also are well above the average for calls against them perhaps offsetting some of the damage.
Moving forward we can examine the net differential for penalty yards within the B1G, so, lets combine penalty yards and the opposition penalty yards to determine who has the best and worst net differentials for penalty yards in the B1G:
Recognize that familiar face? Yes, it’s Nebraska at the top again, where we experience a differential of 12.31 yards per game. We are called for more penalties than anyone in the B1G and combined with our opponent’s penalties makes us the overall leader. Ohio St and Mich St both also experience some of this bias while Wisconsin’s differential mostly offsetting. If it feels a bit biased when you play Northwestern, Penn St or Iowa you’re probably not wrong with those three teams each experiencing a 10.72, 12.67 and 14.72 yard penalty differential against B1G opponents.
Now that we’ve established Nebraska’s position within the B1G let’s address the first complaint that people will make, “Nebraska is just a sloppy team saying they are above average doesn’t prove anything.” It’s a valid point that we can hopefully address with the next set of analysis. Let’s revisit the first assumption we’ve made and hopefully shown earlier, as the season progresses teams improve and seem to experience less penalties overall and less yards per game in penalties. Even if Nebraska is a sloppy team that experiences more penalties and their opponents aren’t called for a lot of penalties they should still see improvement if the first assumption is true.
The second assumption addresses this improvement metric by comparing calls made outside of the B1G conference with those made within. If Nebraska above all the other B1G teams sees the worst amount of improvement moving from OOC to within Conference I would argue that it’s difficult not to see the presence of at least some bias. With that being said, let’s dive on in:
For 2011, Nebraska’s rank for all of the FBS was 22nd in yards per game called against their opponents when we look at just within the conference their place fell to 55th with opponents being called for 7.4 less yards per game within the B1G over the OOC games. So the argument that they were a sloppy team (ranked 22nd) seems like an unfair argument to make and yet when we only look at the B1G games they saw huge reductions in calls against their opponents. 2011 saw Nebraska play a mix of some of the worst culprits for penalties Mich St was 80th overall and 92 within the conference differential of 15 penalty yards per game over the average as well as teams like Wisconsin ranked 16th and 11th with a differential of -12. So I would suggest that the argument about Nebraska only playing disciplined conference opponents doesn’t hold up.
Spoiler alert! This trend holds for all 8 years that Nebraska has been within the B1G, we have never seen a single season where calls against our opponents within the B1G improve.
Overall the trends look like this for all teams:
Nebraska fell 17.5 ranks on average in the FBS when we compare all games to within conference games while teams like Michigan and Iowa moved up places over the 8 years. The average for the B1G was -2.32 with a SD of 6.36, although the sample size is small it’s a big leap to fall so far so often for Nebraska. Over 8 years across the OOC and within Conference games our opponents consistently get called for 5.78 less yards per game as we move to play teams within the B1G. Maryland is the only team that’s even close but still saw at least three years where they improved in position. Interestingly the B1G generally sees little improvement in opposition penalty yards per game moving within conference with Iowa and Purdue being the only teams that see benefits to moving into Conference play.
But maybe Nebraska always just starts highly ranked because our OOC schedule is weak and those teams get called for a lot of penalties so moving into Conference play is always going offset that. Well let’s examine that as well:
Whether it was years where we started 22nd or years that we started 109th we always saw a rank reduction and a penalty yards per game reduction moving into the B1G. Now let’s move into whether this holds up when we examine Nebraska’s penalties instead of just their opposition’s calls.
The results seem to indicate that Nebraska experiences improvement moving from OOC to within the Conference about 8.5 ranks of improvement and 1.99 less yards per game in penalties moving into the B1G from OOC. Indiana sees the most benefit while Wisconsin seems to experience the least indicating more severe officiating within conference. What is telling to me about this stat is that it shows Nebraska does improve their sloppiness as a team leading to a reduction in penalty yards and yet somehow every single season our opponents improve at a better rate. We reduce our penalties game to game over the course of a season and yet the other B1G teams improve more than we do when we play against them which leads to us never having a single season of improvement for opposition penalties called when we play them. Let’s finally compare the net yards as we did with the means for the B1G to see what it looks like when you combine calls against your opponents when you play them and calls against your team.
Overall Nebraska still ranks second to last in this category experiencing a net reduction in benefit moving into B1G play from OOC. In fact, 8 of the 14 teams experience more severe punishment moving into the B1G despite the metric provided for assumption 1 suggesting that teams really do improve as the season progresses.
tldr; Almost 3000 words later let’s recap what we’ve found: Nebraska has the worst net differential in yards within the B1G combining both calls against their opponents when they play and calls against Nebraska over the 8 years. The argument that over the last 8 years Nebraska has just been a sloppy team is unfounded, some years we are high, some years we are low.
Teams generally improve over the course of the season reducing their penalty yardage and overall penalties. In spite of this, Nebraska is second to last in the B1G moving from OOC to within Conference play with a net differential of 3.79 yards per game. Combining the results of the OOC to within Conference and the Overall B1G stats the net yardages look like this:
Nebraska sees the 2nd least benefit moving into conference play, and the worst within conference benefit in the B1G.
To answer the question of whether Nebraska sees bias in officiating within the B1G I would suggest that it is hard to argue against this premise given these results. There are of course limitations to this analysis such as the non-inclusion of accepted versus not accepted penalties however, I’m not sure they would change the results all that much. I’ve tried to control for a lot of the possible counter arguments against the notion of at least some bias in officiating while still recognizing that 8 years of data isn’t necessarily large enough to draw generalizations and conclusions from. These results could all be within the margin of error given the relatively low n.
If anyone has any suggestions to improve on any of this don’t hesitate to comment.
******
Said that he worked about 20 hours on this. Kudos to this guy for his work on this.
