## Thursday, January 26, 2023

### 2022 Yards Per Play: ACC

Next up in our conference breakdowns is the ACC.

Here are the 2022 ACC 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 ACC 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 2022 season, which teams in the ACC met this threshold? Here are ACC teams sorted by performance over what would be expected from their Net YPP numbers.
Clemson significantly exceeded their expected record (more on them later) while Florida State and Virginia underachieved relative to their YPP numbers. Clemson won all their one-score ACC games, finishing 3-0 in such contests. Each close victory also came against division opponents, giving them a leg up in the conference race. Florida State was not terrible in one-score conference games, finishing 1-2. However, they were absurdly dominant in most of their conference wins. Four of their five ACC victories came by at least 25 points. Mike Norvell should have found a way to save some of those excess points for later. Virginia was 1-3 in close conference games and also finished with the second worst in-conference turnover margin (-6) making life rough for first year head coach Tony Elliott

Worst Unbeaten Power Five Teams
For all the talk of their demise, Clemson did win the ACC for the seventh time in eight seasons in 2022. They also finished unbeaten in ACC play for the first time since 2019. However, you didn't have to squint too hard to see this team's warts. While their defense was one of the best in the ACC, their offense was below average in league play. And their non-conference performance left a lot to be desired. Notre Dame whipped them in South Bend, South Carolina beat them for the first time since 2013, and Tennessee (sans their starting quarterback) handled them in the Orange Bowl. Their unbeaten ACC record probably says a lot more about the state of the conference in 2022 than it does bout their own prowess. In fact, as far as unbeaten Power Five teams go, Clemson was historically bad (or more accurately, mediocre) in 2022.

As I often mention, I have been tracking YPP data back to 2005. In those 18 seasons, only six Power Five (formerly BCS) teams have finished unbeaten in conference play with a YPP Net of less than 1.00. Those six teams are listed in the following table sorted by YPP Net.
There are technically six teams that qualified for this table, but Southern Cal should have a big ole asterisk. I know college football seasons can run together, but remember the 2020 season was played in the midst of a global pandemic. The Pac-12 initially decided not to play football, but eventually played an abbreviated campaign beginning in November. The Trojans won all five of their regular season games, including several in improbable fashion, all while barely outgaining their opponents on a per play basis. Had the Pac-12 played a standard schedule, its unlikely the Trojans could have continued their improbable run, but they did win all their scheduled regular season conference games. The Pac-12 Championship Game was a different story, but remember, I don't include championship games in the YPP stats. Anyway, whether or not we include Southern Cal in this analysis, its clear Clemson enjoyed an historic season in 2022. The Tigers became just the fourth team to finish unbeaten in conference play, finish with a YPP Net of less than 1.00, and win their conference championship game (Southern Cal and Iowa dropped their respective title games). I don't know if all of that will fit on a t-shirt, but Clemson fans can always check Tee Public to see.

Before we close, I think it is helpful to see how those five previous teams performed the following season. Finishing unbeaten in conference play often requires at least a small amount of good fortune and with a YPP Net of less than 1.00, it probably required some additional good bounces. It would stand to reason then, that these teams would see some regression the following season. And that is exactly what we see (teams in the table are listed chronologically).
If we include Southern Cal, this quintet declined from perfection to mediocrity. If we ignore Southern Cal, the decline is still significant, though not nearly as steep. However, the main thing to remember here is sample size. Five (or four) teams is hardly a representative sample. I'd bet against Clemson finishing with a perfect ACC record next year, but I don't think they are in store for a Tommy West style season. Despite his lofty hateability rating, Dabo is at least partially self-aware when it comes to football matters. He fired his offensive coordinator and replaced him with the OC from the national runner up. Clemson may not be as fortunate as they were this past season, but they will probably be better, much to the haters' (myself included) chagrin.