Back many decades of a couple of weeks ago, before the season was officially canceled, the Big 10 released a conference football schedule for the fall of 2020.  While the MGoBlog staff weren't too bothered by Michigan's difficult schedule, I was probably more upset than I should be.   In my head it seemed like once again Ohio State was avoiding all the most difficult division crossover matchups (Wisconsin, Minnesota) and Michigan was getting stuck with short end of the SOS stick once more.  It felt like OSU just does this year after year and regularly avoids the best non Michigan/PSU Big 10 team on their schedule.  Them missing a top 5 2017 Wisconsin team (in the regular season) and an ass kicking 2002 Iowa team stuck out as prime examples of this.  

I then realized if I can only think of a couple of examples, I'm probably just seeing things through my maize and blue tinted glasses, and surely any competitive advantages one team has had would have evened themselves out throughout the years.  Nevertheless, the idea that OSU has had an easier schedule over the years gnawed at me and I decided to do an in depth comparison of the two teams' schedules to see for sure.  

Now comparing two teams' schedule strength is a difficult thing to do, as you penalize good teams because their strength of schedule will go down from beating so many of the teams on the schedule.  I tried to eliminate this problem by not counting the results of games OSU and UM played in on their respective opponents' win loss records.  Also, I didn't include their record when playing against each other as this would have really penalized OSU who have had a dominant record against us (sigh) and have been the better team in the time period I'm looking at.  What time period am I looking at?  Well you can probably figure that out from the diary title, but I'll tell you anyways. I decided to track from 1990 as that is about the time I can start remembering cheering for Michigan (born in 1980) and that would give us a nice even 30 years of data.  I think 30 years is a long enough time period that strength of schedule differences should mostly level themselves out, and I believe the adjustments I mentioned above will make it so that we can get a fair strength of schedule comparison between these two teams that doesn't penalize the better team.  

A couple other notes.  I'm using College Football Reference's Simple Rating System (SRS) to compare opponents as it is the only metric I can find from before 2004 to rate all college football teams and not just the top 25.  It's not the best evaluatory metric ever made as it only uses point differential and strength of schedule to rate teams (it's quite simple as it claims), but it's better than nothing and gives us another data point than just wins and losses.  Also, since it uses SOS in its formula, that should help to negate any opponent's SRS going down too much for losing to a strong OSU or Michigan team. Finally, I only counted regular season Big Ten games and not the championship game, as I'm only interested in the SOS that the schedule makers established prior to the season.  

So, without further ado, here are my data and findings. 

Table 1 - Big Ten Opponents' SRS Scores and Conference Records

 

(To reiterate, I did not count opponents' record against UM and OSU in their respective Big 10 records.  For example, in 1990 Illinois went 6-2 in conference.  They beat OSU and lost to UM, so their record goes as 5-2 for OSU and 6-1 for Michigan.  This should negate most of the advantage a worse team gets in opponent record comparisons.  Also, OSU's SRS score was not counted in Michigan's opponents' average, and the same goes for UM's SRS score in OSU's opponents' average.)

As you can see, Michigan has had a more difficult schedule in every category.  Their opponents have a higher average SRS score, a better average SRS ranking, a better win percentage, and Michigan has had the harder schedule in 19 of 30 years according to SRS and 18 of 30 years according to opponent win percentage.  OSU had the harder schedule less than one third of the time.  I was expecting this to show Michigan has had a more difficult go in the Big Ten, but the results being so one sided was a bit staggering.  If you're confused by SRS, I'll get into that more a bit later, but for now just know that it considered Michigan's opponents to be better than OSU's. 

Tables 2 and 3 - UM and OSU Big Ten Records Side by Side

I wanted to see if my logic wasn't working, and that maybe winning teams were getting penalized in terms of their opponents' record.  As you can see from the top table, Michigan was the more successful team from 1990-2004, while OSU was the much, much more successful team from 2005-2019.  I kept in their head to head records to show that while Michigan only won 2.4% more of their games from that initial time period, that went up to 6.2% if you counted their record in The Game as well.   Similarly, OSU won 22% more of their games from the more recent time period, but that goes all the way up to 29% if you count head to head matchups.  Michigan was clearly better than OSU during the first half of this time frame, but OSU was light years better than Michigan during the second half (just an FYI, in only three years Rich Rod was responsible for 15 games of the 36 OSU was ahead of Michigan from '05-'19). 

Despite these massive differences in their fortunes during these two 15 year periods, you can see from the bottom table that their opponents' win percentages stayed remarkably stagnant.  From '90-'04 OSU's non-UM opponents won 45.6% of the time, and that actually went slightly up to 46.3% during their more successful '05-'19 seasons.  UM's opponents win percentage went from 50% to 48.4% in the same respective periods.  With this system I'm using, there doesn't seem to be any correlation between either teams' winning and their opponents losing.  In fact, it should be that if UM wins more than OSU that will hurt OSU's opponent's record, and vice versa, as their shared conference opponents record will get worse from UM beating them more.  (Sorry to keep harping on this, but I can foresee some OSU fan seeing this data and saying "Of course UM had the harder schedule, OSU was the better team so their opponents had a worse record."  I want to make it clear that that the way I've recorded the data negates that argument.)  

You can also see that SRS agreed with the opponents' record data, and that it saw Michigan's schedule as the more difficult in both 15 year periods.  Michigan's opponents were about .75 points better in SRS, or about 2.5 rankings higher, on average from '90-'04, and .82 points better, or about 6.5 rankings higher, on average from '05-'19.  This might actually be a case of OSU's success hurting their opponents' SRS.  As point differential is half the SRS formula, the fact that they've been crushing a lot of teams over the past 15 years might be bringing down their opponents' SRS score.  I don't know if it's enough to overcome the difference in the boost that it would give to their opponents' SOS from playing an ass beating OSU, but it might be and I thought it was worth noting.   

So, it's pretty clear Michigan has played the more difficult Big Ten teams of the past 30 years, let's see who has avoided playing more good teams over that time.  

 Tables 4 and 5 - Missed Big Ten Opponents by SRS

I broke Big Ten teams into five tiers based on their SRS scores and where that generally correlates with the national rankings.  A team with an SRS score of 15 is generally between the 5th and 10th best team in the country, so I made that scores 15 or above into tier one.  The best teams are usually somewhere in the low 20s, but I've seen teams as high as 27.  A 10 is usually around the mid-20s in the rankings, so 10-14.99 is tier two, etc., etc.  You can see the tiers for yourself in the table.  From just a winning perspective (not what the fans want to see) you want to avoid teams in the top two tiers, are indifferent about missing teams from the 3rd and 4th tier, and definitely don't want to miss teams from those bottom two tiers as those are almost guaranteed wins.  I made that bottom tier brown, because those teams are absolute dog shit.  

Omitting their head to head games, over the past 30 years Michigan and OSU have played 214 Big Ten regular season games each.  Of those 214, 165 have come against common opponents.  The other 49 have been against a team only one of them has played.  These tables show the quality of the opponents that either one or both teams missed.  

The common opponents both OSU and UM have missed are included in the top table, but in the second table those 25 common opponents are omitted and you're left with just the 49 opponents only one of OSU or Michigan played.  The data are pretty remarkable.  You can see that not only has OSU missed a lot more top opponents than Michigan, played a lot more of the dog shit opponents that UM missed, but also that their quality of opponent missed was higher in nearly every tier.  This is not ideal from a competitive balance standpoint.  

Hard to believe, huh?  Well, maybe you just think SRS is a full of shit metric.  Okay, let's take a look at the records of missed opponents then.  

Table 6 - Missed Big Ten Opponents by Win %

I'll admit, this data absolutely floored me.  Let me explain the table.  For each of the three time periods you have the same four columns.  The top column, "Missed Opp's Total" is the Big 10 record of all the teams OSU or UM missed during that time period.  Below that, in the "Minus Common" column is the top column numbers minus the record of team's that both UM and OSU did not play.  In '90-'04 that was only two teams, in '05-'19 that was a lot more.  That "Minus Common" column therefore gives you the record of teams that only OSU missed on the OSU side, and teams only Michigan missed on the UM side. The next column down is UM's record versus the teams that OSU missed on the OSU side, and OSU's record against teams Michigan missed on the UM side.  The final column is OSU or UM's record subtracted from the "Minus Common" column, so that you get a record for opponents that does not include any games that UM or OSU participated in.  

I'm blown away by this table.  Remember, you want to miss better opponents and play worse ones to have a better chance at winning more.  In this sense OSU is absolutely crushing Michigan.  The opponents Michigan missed over 30 years have won at a 37.6% rate.  OSU's are at 55.4%.  That's a 17.8% difference.  In only 352 games, Michigan's opponents that OSU didn't play have been 62.5 games better than OSU's opponents that Michigan didn't play. OSU was eight games better than Michigan in their 49 games against non common opponents, and I'm not even disappointed in Michigan cause their schedule was so much tougher.  Even in the era that Michigan was clearly better, OSU picked up three games on Michigan against just 25 opponents. OSU misses quality team after quality team, while Michigan just avoids the trash.  That seems....unbalanced.  If Thanos were a Michigan fan he would have snapped away the Big Ten schedule makers by this point.  

Again, don't give me any of that "It's because OSU is so much better!" bullshit, as any influence from games OSU was involved in has been removed from Michigan's opponent's record and vice versa.  This is just 30 years of unbelievably one sided luck.  

Okay, I've had my little rant, let's try to quantify how much this schedule disparity has benefitted OSU and hurt Michigan.   

Tables 7 and 8 - Win % vs. Tier and Expected Wins with Reversed Schedule

 

To try to figure out this unanswerable question of how much the schedule imbalance affected Michigan and OSU, I again went to the SRS tiers and looked at how each team did against said tiers.  OSU won 55.9% of games against the top tier, 60.7% against the second tier and so on.  You can see Michigan's percentages on the right.  Using those percentages as a basis for the percentage of games OSU and UM would win against teams in those tiers if they had to do it again, I then switched each team's schedule over the past 30 years and multiplied each tier by their respective win percentage.  So, if Michigan had OSU's schedule, they would have played 15 tier one teams.  At a 36.8 win percentage that would give them 6.26 expected wins.  You can see the results of those calculations in the lower tables.  Doing that for each team's full schedule I got OSU going from 177 to 174.7 wins with UM's schedule, and UM going from 156 to 160.7 wins with OSU's schedule.  In total that was a seven win swing between the teams.  

When I did this, I felt seven wins felt like too little of a change with that kind of schedule disparity.  However, I do thing a seven win swing in 214 games is fairly significant.  As a passionate fan, I would definitely like to have those wins.  Also, I do think this calculation gives the low end of the expected wins spectrum.  This is because the win percentages I calculated were based on an unbalanced schedule to start with (which I think I've thoroughly shown already), and therefore skews the percentages in favor of OSU.  Second of all, the Rich Rod era really threw off Michigan's numbers as in his three seasons Michigan performed so far below their norm that they likely brought down Michigan's winning percentage appreciably.  OSU had a bad, abnormal year under Fickell as well, but it wasn't the drastic outlier the three Rodriguez* teams were.  They were the three worst SRS rated teams of the last 30 years, and they went 6-15 against the Big Ten during them.  Even though Rodriguez only coached 10% of the years looked at in this study, he was responsible for two of the three (67%) losses against the red tier above (the other was Carr in '96 losing a shocker to a terrible Purdue team), and five of the 12 (41.6%) losses to teams in the grey tier.  This just goes to say it's impossible to accurately predict hypothetical situations like this, but due to those factors I mentioned, had Michigan and OSU's schedules been reversed over the past 30 years, a 7 game swing in wins in Michigan's favor is probably the minimum that would have happened, and likely it would have been at least a couple more games.  

*My point isn't to shit on Rodriguez here.  That has been done plenty by Michigan fans already.  I actually loved the hire and really supported him for about 2.5 years, clinging to the belief that he would turn things around until it was clear he couldn't.  But looking at these data it's shocking just how poor of a job he did.  I know he didn't get enough support from fans and people behind the scenes, but to be at the helm of the three worst teams in a 30 year period in his only three years on the job is unbelievably bad.  

SP+ Gets Involved

Oh, in case you're wondering I looked at SP+ data from this period as well in the years that it was available.  I couldn't find 2019 or before 2004, but I do have the data from 2005-2018 seasons.  I'm tired of taking screenshots, so I'm just going to write the data down here instead of making it pretty.  

From 2005-2018 OSU's opponents had an average SP+ score of 6.26 and an average ranking of 50.08.  UM's opponents were 7.31 and 47.54 respectively.  The rankings are slightly closer than SRS rankings, but not by much.  OSU's missed opponents scored an average of 6.37 to SP+ for an average ranking of 49.79, while UM's missed opponents averaged 4.05 and 55.09.  SP+ rated both teams' missed opponents slightly higher than SRS, but the difference between their schedules was very similar according to both metrics.  It's so similar it's not really worth expanding on, but it is good to know that it doesn't dispute any of the data from above.

 

Discussion

To be clear, I don't believe that this SOS imbalance is due to a Big Ten conspiracy or anything.  I think the schedules are generally made a few years in advance, and so the schedule makers can't anticipate when a '95 Northwestern is going to come out of the blue and go 8-0 in conference. Furthermore, with there being too many teams in the conference for everyone to play everyone, making a fair schedule for all teams is pretty much impossible.   However, circling back to what I said in the intro about being upset about Michigan's 2020 schedule, this was the year the schedule makers had pretty much free reign to schedule any matchup they wanted.  Surely, they must review the previous year's strength of schedule ratings after each season, right?  They must know that the Big Ten schedule has been particularly favorable to OSU and quite difficult for Michigan, no?  Would this not have been a good year to switch things up and give Michigan a favorable schedule?  Am I the asshole here?  

I'm frustrated, and here comes the part where I whine like a baby.  OSU football has the upper hand on Michigan in so many ways.  They are based in a more populated and more football talent rich state.  Furthermore, they don't share that state with another Power 5 conference team.  They really only have one rival to focus on, while we have three.  They're much looser with NCAA rules, and they are not as academically demanding.  They already have so many damn advantages, can we not have an uphill battle when it comes to the schedule as well?  God fucking damn it!  Just one goddamn year!!  I'm not even asking for us to get the easier schedule, just at least make it fair for this One. Damn. Year.

Okay, sorry, I had to get that out of my system.  I know that the schedule doesn't matter as much as the fact that we just can't beat OSU head to head, and no matter how difficult or easy the rest of our schedule is, we won't break through that glass ceiling until we actually beat them.  Still though, it would be nice to have some parity in opponent difficulty.  

Is there anything the Big Ten could do to make the schedules more fair between top teams in the future?  

I don't really have a good idea, and I don't think the conference really cares that much about making this happen.  It is actually one of the charms about college football in how unbalanced things are (see Clemson/Oklahoma's roads to the playoff), and the discussion and arguments that imbalance sets off.  I think the Big Ten going to a nine game schedule was a good start to more parity, but that still leaves four teams off everyone's schedule and so avoiding uneven schedules is almost an impossibility. I think a Scottish Premier League split schedule would be fun, but don't see it as feasible in college football.  It seems like going to a 20 team conference, with two 10 team divisions where everyone plays everyone is the only truly egalitarian system, but to be honest I don't like that idea.  I much preferred the conference at 12 teams when we added Nebraska, and don't really want to water it down more with additional crappy teams.  I guess what I really want is Michigan to be so good that they win the conference despite having a more difficult schedule.  

I'm worn out from writing this so I'm just going to post this now.  I hope you enjoy reading this and that it's a pleasant distraction from all the craziness going on in the world right now.