## Wednesday, April 19, 2017

### 2016 Yards Per Play: Pac-12

Seven conferences down, three to go. This week, we head even further west and examine the Pac-12. Here are the 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, 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 2016 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.
Four Pac-12 teams saw their expected record differ significantly from their actual record. Colorado and Washington State vastly over-performed relative to their expected record while Arizona and UCLA under-performed. Colorado went from the basement to the penthouse thanks to better play, but also thanks to a 3-1 record in one-score conference games, including a 10-5 baseball slugfest against Stanford which featured a Todd Helton grandslam. Washington State opened 2016 with a loss to an FCS opponent for the second consecutive season, but went 3-0 in one-score conference games to put themselves in contention for the North division title. Arizona suffered through a great deal of injuries en route to their worst conference record since 2003, but they were not particularly unlucky in one-score games. No, the Wildcats can blame turnovers. They forced only six in Pac-12 play while committing 19. Their in-conference turnover margin of -13 was eight worse than the team with the second worst in-conference turnover margin, Oregon. Finally, UCLA began the year in the top-20, but finished just 4-8 (2-7 in Pac-12 play). The Bruins also suffered through their share of injuries, but were mostly done in by their poor record in close games (0-3 in one-score conference games).