## Thursday, April 01, 2021

### 2020 Yards Per Play: MAC

This week, we examine the MAC, a conference that started late but managed to have two teams finished ranked in the AP Poll for the first time since 2003.

Here are the 2020 MAC standings.
So we know what each team achieved, but how did they perform? To answer that, here are the Yards Per Play (YPP), Yards Per Play Allowed (YPA) and Net Yards Per Play (Net) numbers for each MAC team. This includes conference play only, with the championship game not included. The teams are sorted by division, by Net YPP with conference rank in parentheses.
College football teams play either eight or nine conference games (typically fewer in 2020). Consequently, their record in such a small sample may not be indicative of their quality of play. A few fortuitous bounces here or there can be the difference between another ho-hum campaign or a special season. Randomness and other factors outside of our perception play a role in determining the standings. It would be fantastic if college football teams played 100 or even 1000 games. Then we could have a better idea about which teams were really the best. Alas, players would miss too much class time, their bodies would be battered beyond recognition, and I would never leave the couch. As it is, we have to make do with the handful of games teams do play. In those games, we can learn a lot from a team’s YPP. Since 2005, I have collected YPP data for every conference. I use conference games only because teams play such divergent non-conference schedules and the teams within a conference tend to be of similar quality. By running a regression analysis between a team’s Net YPP (the difference between their Yards Per Play and Yards Per Play Allowed) and their conference winning percentage, we can see if Net YPP is a decent predictor of a team’s record. Spoiler alert. It is. For the statistically inclined, the correlation coefficient between a team’s Net YPP in conference play and their conference record is around .66. Since Net YPP is a solid predictor of a team’s conference record, we can use it to identify which teams had a significant disparity between their conference record as predicted by Net YPP and their actual conference record. I used a difference of .200 between predicted and actual winning percentage as the threshold for ‘significant’. Why .200? It is a little arbitrary, but .200 corresponds to a difference of 1.6 games over an eight game conference schedule and 1.8 games over a nine game one. Over or under-performing by more than a game and a half in a small sample seems significant to me. In the 2020 season, which teams in the MAC met this threshold? Here are MAC teams sorted by performance over what would be expected from their Net YPP numbers.
Eventual MAC champ Ball State significantly exceeded their expected record as did Akron. For Ball State, it was all about close game performance. The Cardinals finished 4-1 in one-score conference games, winning all their tight games after dropping their opener by a touchdown to Miami. Meanwhile, Akron was not especially lucky, they just happened to be really bad and benefited from beating a team that was statically a little better than they were. That team happened to be Bowling Green. While the Falcons significantly under-achieved relative to their YPP numbers, they were still quite bad; just not catastrophic. In five games, Bowling Green forced just a single turnover, while committing eleven, for a MAC worst turnover margin of -10.

What's the Deal with the MAC Championship Game?
In the 2020 MAC Championship Game, an undefeated Buffalo team entered as a nearly two touchdown favorite against an upstart outfit from Muncie, Indiana that had not finished with a winning record since 2013. The upstarts traded scores with Buffalo for a quarter and a change before a pair of touchdowns with under two minutes to go in the half (including a scoop and score) gave them some breathing room. In the second half, Buffalo put together some nice drives, but capped those drives with a touchdown just once and Ball State was able to escape Detroit with their first MAC title since 1996. The upset was not out of character for the MAC Championship Game. The last three games have been won outright by underdogs, and underdogs have covered the past five games. Overall, the MAC Championship Game has not gone well for the betting favorite, particularly Against the Spread (ATS).
In nearly a quarter century of action, the betting favorite has won the game outright just around 58% of the time. That isn't great, especially considering some of the larger spreads in the history of the game. However, their performance ATS has been ghastly. They have covered just 26% of the time! To put that number in perspective, if you had blindly placed the same monetary bet on the underdog plus the points in each MAC Championship Game, your rate of return would be over 41%!

It certainly appears the MAC Championship Game is a destination where favorites go to die, or at least kill the profits of their investors. However, before we make any bold proclamations, we need to compare the MAC to other Group of Five (G5) conferences. The MAC was the second non-power conference to hold a championship game (after the WAC in 1996), but does have the longest running championship game among the G5 since the WAC's championship tilt lasted just three seasons. With the Sun Belt adding a title game in 2018, all the current G5 conferences have a championship game. Here is how all those other title games have played out for favoites, both straight up and ATS.
Compared to the MAC, favorites in the other G5 conferences have fared much better in winning the title outright. They have won about 71% of the time (versus about 58% for MAC favorites). However, like MAC favorites, they do have a losing record ATS, although their winning percentage (44%) is much higher than those of MAC favorites (26%). Why is this? Why do MAC favorites struggle in their title games as compared to other G5 favorites? I think the biggest culprit is the venue.

In the early days of the MAC Championship Game, when Marshall was the dominant program, it was played at campus sites. The team with the best conference record got to host the game for the first seven seasons of its existence. However, since 2004, the game has been played on a neutral site in Detroit, Michigan. That makes the MAC an outlier among the G5. Every other conference rewards their best regular season team by allowing them to host the title game (the 2020 Mountain West Championship Game was played in Las Vegas because public health restrictions in California prevented San Jose State from hosting the game). When you compare MAC favorites to other G5 favorites and consider venue, the MAC results don't seem so bizarre.
The MAC doesn't have a very large sample of home favorites, but the fact their home favorites never lost in four tries compares favorably to the 21-6 straight up record of the other G5 home favorites. Their ATS record, while .333 is just one game away from .500 which would equal the ATS record of the other G5 favorites.
When it comes to road favorites, MAC favorites have actually done better than other G5 favorites in a very limited (and not statistically valid) sample, both straight up and ATS.
The neutral field is where MAC favorites have struggled. MAC favorites have played four times as many games on a neutral field as the other G5 combined. In addition, most of those other G5 neutral site title games came last century. If the MAC rewarded its best teams with homefield advantage, these upsets would slowly go the way of the WAC
What's the deal with the MAC?
I for one, knew they would be back.