Thursday, February 08, 2024

2023 Yards Per Play: Big 10

Two conferences down. Eight to go. We head (mid) west this week and examine the Big 10. 

Here are the 2023 Big 10 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 Big 10 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. 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 2023 season, which teams in the Big 10 met this threshold? Here are Big 10 teams sorted by performance over what would be expected from their Net YPP numbers.
Iowa and Michigan significantly exceeded their expected record based on YPP while Nebraska and Illinois underachieved. Iowa and Michigan combined to finish 6-1 in one-score conference games and the Wolverines finished with the second best in-conference turnover margin (+15) in the Big 10. Meanwhile, Illinois and Nebraska has the two worst in-conference turnover margins in the Big 10 with the Illini finishing seven turnovers in the hole while Nebraska turned the ball over fifteen more times than their league foes. The Cornhuskers also finished 1-5 in one-score conference games, continuing an incredible trend I shall henceforth refer to as the Curse of Bo Pelini
Outliers
Iowa was bad on offense in 2023. That is not a controversial or surprising statement. Their nepo offensive coordinator was under fire before the season began thanks to their lackluster performance throughout his tenure. In order to keep his job, the Iowa offense had to average at least 25 points per game in 2023. That number included any points scored by the defense or special teams which have been fantastic over the past few seasons. The Hawkeyes just missed their goal of 25 points per game by roughly ten points. Per game. Iowa averaged 15.4 points per game in 2023 and ranked second to last in scoring offense (only Kent State averaged less). As you may have noticed from the YPP table, their per play offensive numbers were also quite bad. The Hawkeyes averaged under four yards per play against Big 10 opponents (3.85). I have YPP numbers going back to 2005, and while the Hawkeyes cannot lay claim to having the worst per play conference offense of any BCS/Power Five team in that span (my alma mater actually holds the record with 3.06 in 2014), they are by far the most successful BCS/Power Five team with a dreadful offense. 

Including Iowa last season, 28 BCS/Power Five teams have averaged less than four yards per play in conference action since 2005. 26 of those 28 teams finished with losing conference records. Iowa, of course, won their division with a 7-2 mark last season and Vanderbilt eked out a 4-4 SEC record in 2008 while averaging 3.96 yards per play. Twelve of 28 teams finished winless in conference play, seven finished with one conference win, six won two league games, and UCLA in 2008 was the only team to win three (two of their three league wins came against teams that also averaged under four yards per play). Combined the 27 teams not named Iowa, finished 26-201 in conference play, averaging less than one league win! The Hawkeyes were not a great team in 2023, but they were one of the most unique teams in recent college football history. 

For the curious, all 28 BCS/Power Five teams that averaged under four yards per play are listed below along with their conference record. 
Non-BCS and Group of Five teams that averaged under four yards per play in conference action did not fare any better. In fact, they were a little worse. Since 2005, fourteen mid-major teams have averaged under four yards per play in league games. Those teams combined for a 9-101 conference record and no team won more than three league games. 

1 comment:

patrick said...

lol Iowa.