## Thursday, April 26, 2018

### 2017 Yards Per Play: Pac-12

We'll stay out west this week as we review the Pac-12. Here are the 2017 Pac-12 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 Pac-12 team. This includes conference play only, championship game excluded. The teams are sorted by division by Net YPP with conference rank in parentheses.
College football teams play either eight or nine conference games. 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 2017 season, which teams in the Pac-12 met this threshold? Here are Pac-12 teams sorted by performance over what would be expected from their Net YPP numbers. Arizona State and Stanford significantly exceeded their expected record based on YPP and no Pac-12 team significantly under-performed relative to their expected record.
Arizona State finished with a decent record in close conference games, winning two of their three contests and the Sun Devils also had a decent in-conference turnover margin of +4. But we’ll have to dig a little deeper to uncover why their expected winning percentage is so low. The Sun Devils played poorly in just two conference games. In losses to the eventual Pac-12 Championship Game participants, Southern Cal, and Stanford, Arizona State was outgained on a per play basis by over two yards per snap (5.80 to 8.05). In their other seven games, the Sun Devils were much more competitive. In those seven contests, they were slightly outgained per play (5.59 to 5.63), yet they managed to win six of them. Credit Todd Graham’s voodoo and the vagaries of an even smaller sample size. Meanwhile, it’s much easier to see why Stanford exceeded their expected record. The Cardinal had the best in-conference turnover margin of any Pac-12 team (+12) and won all four of their one-score conference games. Those close games, especially the Friday night tilt with Washington, decided the Pac-12 North. That close game good fortune continued a trend under David Shaw. Since Shaw’s arrival on The Farm prior to the 2011 season, Stanford is 16-8 in one-score conference games.

The 2017 Pac-12 Championship Game was a rematch (or is it re-imagining?) of the 2015 Pac-12 Championship Game. Southern Cal was able to exact a modicum of revenge and claim their first ever Pac-12 title and first conference title since 2008! But, let’s go back to the 2015 game. Southern Cal won their first Pac-12 South title that season. It also marked the fourth consecutive year a different team won the division (with no repeats). Allow me to explain. UCLA won the South in 2012, Arizona State won it in 2013, Arizona won in 2014, and Southern Cal won in 2015. Colorado would extend the streak to five in 2016 before Southern Cal ended it in 2017.
How rare is a run of five unique champions in five seasons? Pretty darn unique. The only other Power Five conference that can boast a similar run is the ACC, with the Coastal division producing a unique champ in the past five seasons.
Outside of the Power Five, one conference can claim a longer streak, but it required some division shuffling which was a direct result of conference expansion.
By the time Rice won the West division of Conference USA, SMU, Houston, and Tulsa were members of the AAC. Louisiana Tech won the division in 2014; their second season in the conference after the WAC’s dissolution. Southern Miss was a charter member of the East division of the conference, but came over to the West following the league’s shifting in 2013.

If Utah can come away with the crown in 2018, every member of the Pac-12 South will have won the division. This would be a remarkable achievement considering the conference did not begin divisional play until 2011. The league would still not be able to match Conference USA in terms of egalitarian streaks, but it would be a distinctive accomplishment in its own right. And if either Virginia or Pitt claim the ACC Coastal in 2018, Conference USA will have company in terms of rotating division winners.

## Thursday, April 19, 2018

### 2017 Adjusted Pythagorean Record: Mountain West

Last week, we looked at how Mountain West teams fared in terms of yards per play. This week, we turn our attention to how the season played out in terms of the Adjusted Pythagorean Record, or APR. For an in-depth look at APR, click here. If you didn’t feel like clicking, here is the Reader’s Digest version. APR looks at how well a team scores and prevents touchdowns. Non-offensive touchdowns, field goals, extra points, and safeties are excluded. The ratio of offensive touchdowns to touchdowns allowed is converted into a winning percentage. Pretty simple actually.

Once again, here are the 2017 Mountain West standings.
And here are the APR standings sorted by division with conference rank in offensive touchdowns, touchdowns allowed, and APR in parentheses. This includes conference games only, with the championship game excluded.
Finally, Mountain West teams are sorted by the difference between their actual number of wins and their expected number of wins according to APR.
Utah State was the only Mountain West team that saw their actual record differ significantly from their APR. Utah State also under-performed based on what we would expect from their YPP numbers and we went over a few reasons for that last week.

In 2017, Wyoming finished with a winning record and participated in a bowl game for the second consecutive season. This marked the first time the Cowboys posted consecutive winning seasons since 1999 when they finished up a run of five straight winning campaigns. However, the Cowboys went about posting those winning records in drastically different ways. In 2016, the Cowboys emerged from out of nowhere to win the Mountain Division of the Mountain West Conference. Led by presumptive first round draft choice Josh Allen as well as a few other future NFL players, the Cowboys were involved in numerous shootouts. In conference play, the Cowboys scored 40 offensive touchdowns while allowing 35. Those 75 total touchdowns meant the average Wyoming conference game featured nearly ten combined offensive touchdowns! Despite Allen’s return in 2017, the Cowboys were not able to overcome their other losses on offense and the team scored just 21 offensive touchdowns in conference play. Fortunately, at the same time the offense was cratering, the defense was getting its act together. The Cowboys allowed just 14 offensive touchdowns in 2017 and the team was in contention for another division title until late November. In 2017, the average Wyoming conference game featured just a little over four combined offensive touchdowns, or less than half of the 2016 total. Whereas in 2016, the Cowboys lost a conference game despite scoring 66 points (just 52 in regulation), in 2017, they won a conference game despite scoring just 16 points. Overall, the 40 touchdown difference in combined offensive touchdowns in conference play marked the third largest decrease since 2005!
In a nice coincidence, the other instances occurred in the same season. Oklahoma went from having one of the best offenses on earth in 2008 to being merely decent on that side of the ball in 2009. However, the defense improved substantially, allowing the Sooners to remain a quality team despite five regular season losses. Nebraska more closely resembles Wyoming as they went from being involved in a lot of shootouts to nearly winning the Big 12 title despite not scoring an offensive touchdown in the title game. Obviously, they had a little more star power on defense than Wyoming, but otherwise, the comparison is apt.

## Thursday, April 12, 2018

### 2017 Yards Per Play: Mountain West

Our next conference is the Mountain West. Here are the 2017 Mountain West 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 Mountain West team. This includes conference play only, championship game excluded. The teams are sorted by division by Net YPP with conference rank in parentheses.
College football teams play either eight or nine conference games. 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 2017 season, which teams in the Mountain West met this threshold? Here are Mountain West teams sorted by performance over what would be expected from their Net YPP numbers.
Air Force significantly over-performed relative to their YPP numbers while Utah State and to a lesser extent, New Mexico, under-performed. Air Force finished 3-1 in close conference games, while New Mexico and Utah State both finished 0-2 in such contests. New Mexico also had an in-conference turnover margin of -12 which was second worst in the Mountain West (more on the worst team later). For Air Force and Utah State, 2017 continued long term trends, at least in regards to over and under-performance, under their respective head coaches.

Troy Calhoun has been in charge at Air Force since 2007. During his eleven seasons in charge of the Falcons, his teams have finished with a winning conference record eight times despite never finishing higher than third in Net YPP. His teams have exceeded their expected conference record based on Net YPP by at least .100 seven times. Overall, his teams have averaged a winning percentage about .122 points higher than would be expected based on their YPP numbers. That equates to nearly one additional conference win over an eight-game season. The table below summarizes what I just said, listing the Falcons Net YPP finish each season under Calhoun as well as the difference in their actual winning percentage and expected winning percentage based on YPP.
Conversely, Utah State teams coached by Matt Wells have tended to under-perform relative to their Net YPP. Wells has been in charge in Logan for five seasons beginning with 2013. His teams have never finished lower than fourth in the conference in Net YPP (the top third in the twelve team Mountain West), and yet his teams have twice finished with non-winning conference records (including a last place divisional finish in 2016). His teams have under-performed by at least .200 twice in five seasons and have over-performed by at least .100 just once. Overall, his teams averaged a winning percentage about .130 points lower than would be expected based on their YPP numbers. That equates to about one fewer conference win over an eight-game season. I have duplicated the previous table with the same stats for Wells’ teams.
With eleven season’s worth of data, teams coached by Troy Calhoun seem to have an ability to win more games than we would otherwise expect based on their Net YPP numbers. With less than half the data, it’s unfair to render judgement on Matt Wells yet. His teams could be in the midst of a slump that breaks in 2018 (his first three teams slightly exceeded their expected record in the aggregate). However, if his teams significantly under-perform again in 2018, it might be time to further scrutinize his in-game decision making.

Before leaving the Mountain West for the week, I wanted to mention San Jose State. The Spartans struggled in their first season under Brent Brennan, winning just one game against an FBS opponent while losing nine games by at least 20 points. The Spartans were bad, but their suckitude was amplified by their awful turnover margin. In conference play, the Spartans turned the ball over 25 times while gaining just eight turnovers of their own for a margin of -17. Since 2005, only four other teams have posted an in-conference turnover margin of at least -2 per game, including a recent Mountain West team. Those teams all improved substantially the following season.
I wouldn’t go purchasing Mountain West Championship Game tickets just yet were I a San Jose State fan, but the Spartans should be much more competitive in 2018.

## Thursday, April 05, 2018

### 2017 Adjusted Pythagorean Record: MAC

Two weeks ago, we looked at how MAC teams fared in terms of yards per play. This week, we turn our attention to how the season played out in terms of the Adjusted Pythagorean Record, or APR. For an in-depth look at APR, click here. If you didn’t feel like clicking, here is the Reader’s Digest version. APR looks at how well a team scores and prevents touchdowns. Non-offensive touchdowns, field goals, extra points, and safeties are excluded. The ratio of offensive touchdowns to touchdowns allowed is converted into a winning percentage. Pretty simple actually.

Once again, here are the 2017 MAC standings.
And here are the APR standings sorted by division with conference rank in offensive touchdowns, touchdowns allowed, and APR in parentheses. This includes conference games only, with the championship game excluded.
Finally, MAC teams are sorted by the difference between their actual number of wins and their expected number of wins according to APR.
I use a game and a half as a line of demarcation to determine if teams drastically over or under perform their APR. By that standard, no MAC teams saw their record differ significantly from their predicted APR.

Ball State was bad in 2017. That’s not a controversial statement. The Cardinals finished 2-10 (0-8 in MAC play) and nine of their ten losses came by double-digits. But its spring, and at least where I live, that means longer days, warmer temperatures, and a deluge of pollen. In other words, after a long cold mild winter, things are looking up. With that in mind, I’m going to give Ball State fans a reason for hope heading into 2018. Here are a few reasons why you should not only be cautiously optimistic regarding the 2018 season, but why you may want to schedule some additional time off work around the holidays to catch the watch Ball State in their bowl game.

2017 was a disaster for Ball State, but the Cardinals endured a historic glut of injuries. Mid-major teams tend to have depth problems regardless, but suffering through a biblical scope of injuries can only tamper down the won/loss record. Consider that before conference play began, the Cardinals nearly upset Illinois (yes, the Illini were bad as well, but it was a road game against a Power 5 opponent) and beat the resurrected UAB Blazers by 20. A team with that level of talent would likely have been competitive in the MAC instead of the winless bunch Ball State eventually became.

Ball State was a sieve defensively last season. They allowed 45 offensive touchdowns in conference play (or more than five and a half per game). Since 2005, that is one of the worst MAC defenses I have ever tracked. See below for a chronological list.
How did those worst of the worst MAC defenses perform the next season? They got better. One of the principle tenets of statistics is that extreme performances are unlikely to be repeated. For a team to play as poorly as Ball State did last season, a lot of things have to go wrong. It is unlikely the same confluence of factors will exist in 2018.
The previous seven bad MAC defenses all improved the next season. Every defense allowed at least five fewer offensive touchdowns and collectively they allowed about eleven fewer on average (almost one and a half per game).

Aside from being quite bad on defense, Ball State was also unlucky in regards to non-offensive touchdowns. The Cardinals allowed eight non-offensive touchdowns (three interception returns, two fumble returns, and three punt block/returns) in MAC play while scoring none of their own. Think about that number for a second. The Cardinals played eight conference games and were net negative eight in non-offensive touchdowns. This means the Cardinals effectively spotted every conference opponent one touchdown. That is very difficult to overcome. Nothing in life is guaranteed, but I would wager a significant sum Ball State does not see a similar rate of non-offensive touchdowns scored against them in 2018. These events are extremely consequential in terms impact, but they are also quite random. Since 2005, only six other teams have had a non-offensive touchdown net in conference play of negative six or worse. Here is how their conference record changed the following season.
Aside from Baylor, which was dying a painful death under Guy Morriss, every other team not only improved, but improved significantly. A similar result for Ball State would not surprise me at all.

Finally, 2018 will be Mike Neu’s third year in charge of the Cardinals. You don’t have to look far to find instances of significant improvement in a coach’s third season. Taken together, all these trends point to marked improvement for Ball State in 2018.