Now is the time of the year when we look at Pythagorean wins. Is it a science? Not exactly, but I do always find it interesting and it's something of a personal tradition.
You can get a more complete background on Pythagorean wins (or expectation) at the link above, but the short version is that it's a way to measure quality based on the idea that wins and losses should be proportional to points scored and allowed. For example, if a football team scored 300 points and allowed 300 points over a 12-game schedule, its Pythagorean expectation would be .500, or six wins.
Here's a real case. In 2019 Ole Miss scored 319 points and allowed 318 for an expected winning percentage of .502, or a win total of 6.02. The Rebels actually won four games, meaning they were two wins below expectation. That's bad in the moment, but it can be good for the season that follows:
Between 2007 and 2016 (1,224 individual seasons), teams that had a Pythagorean expectation that was 1.6 wins or more greater than the actual win total improved by at least one win 76.3 percent of the time. On average, those teams improved by 1.96 wins.
The correlation isn’t quite as strong on the other end, but teams that were 1.6 expected wins or more below the actual total had a lower win total the following year 68.6 percent of the time and averaged 2.2 fewer wins.
I updated those numbers through the end of the 2019 regular season, so adding in win-total changes from 2017 and 2018. Between 2007 and 2018, there have been 108 teams that were at least 1.6 wins below expectation. Eighty of those 108 teams (74.1%) had an improved win total the following season. On average, a team in that group improved by 2.2 wins the following season.
On the other side of the equation there were 84 teams that were 1.6 wins above expectation (i.e. their record was better than their actual quality). Fifty-seven from that group (67.9%) saw their win total decrease the following season. Overall, that group saw 2.2 fewer wins on average the following season.
Later this week, I'll look at which 2019 teams were on the good and bad sides of the Pythagorean divide, but first I wanted to revisit our 2018 winners and losers. Last season there were eight teams that had 1.6 or more wins below expectation:
| TEAM | 2018 RECORD | EXP. WINS | DIFF. | 2019 WINS |
| Mississippi St. | 8-4 | 10.7 | 2.7 | 6 |
| Miami | 7-5 | 9.4 | 2.4 | 6 |
| Texas Tech | 5-7 | 7.3 | 2.3 | 4 |
| Air Force | 5-7 | 7.1 | 2.1 | 10 |
| UNC | 2-9 | 4.0 | 2.0 | 6 |
| Nebraska | 4-8 | 5.7 | 1.7 | 5 |
| Iowa | 8-4 | 9.6 | 1.6 | 9 |
| San Jose St. | 1-11 | 2.6 | 1.6 | 5 |
The three teams with the greatest difference between wins and expectation all had lower win totals, which is a bit out of the ordinary. All three were somewhat unique cases. Mississippi State lost a ton of talent ton defense from a better-than-it-looked 2018 team, then stacked a bunch of 2019 suspensions on top of it. Miami lost its defensive coordinator last year, then lost its head coach, then got its defensive coordinator back but as its head coach. The 2018 Hurricanes were probably better than their record and the 2019 Hurricanes went all the way to the other end of the equation. So did Texas Tech in its first season under head coach Matt Wells. Both teams will show up on one of the "surprise" lists later this week.
Below the top three, the remaining five teams (62.5%) all improved their win totals. Air Force (+5 wins) and San Jose State (+4 wins) are perfect examples of teams making gains the year before that showed up the following season. The North Carolina team Mack Brown inherited wasn't quite as bad as it looked and that showed in 2019. Iowa improved by one win, as did Nebraska. Of course, that latter case shows the limitations of just counting win totals. Technically the Huskers belong in the "improved their win total" group, but the 2019 season hardly felt like a success.
Here are the six teams that were ahead of the game at the end of last season and thus were more likely to see their win totals decrease in 2019:
| TEAM | 2018 RECORD | EXP. WINS | DIFF. | 2019 WINS |
| Oklahoma | 12-1 | 9.5 | -2.5 | 12 |
| Hawaii | 8-5 | 5.8 | -2.2 | 9 |
| Notre Dame | 12-0 | 10.0 | -2.0 | 10 |
| Ohio St. | 12-1 | 10.1 | -1.9 | 13 |
| NIU | 8-5 | 6.2 | -1.8 | 5 |
| UCF | 12-0 | 10.2 | -1.8 | 9 |
Part of the reason the correlation isn't quite as strong at this end of the spectrum is because of strong seasons from traditional powers. Lose one or fewer games and it's almost inevitable that your expectation will be lower than your actual total. In some cases, that can be notable but programs like Oklahoma and Ohio State are well-established at this point. They consistently outperform expectations slightly and its rarely a sign of trouble.
For other teams, however, those special seasons can be a reflection of some randomness. UCF was ahead of the game in 2017 and 2018, but it's regular-season win total didn't drop until this year. Notre Dame took a slight step back, as the Pythagorean formula indicated was likely going to be the case. Hawaii bucked the trend. Northern Illinois, a team that went 8-5 in 2018 despite being outscored on the season, did not.
That's how Pythagorean expectation performed on the extreme ends of the scale for 2018.
The Grab Bag
- Cam Mack recorded the first triple-double in program history as Nebraska got a nice win over Pudue. (3 Takeaways, Photos)
- Nebraska picked up two commitments on Sunday: Niko Cooper, Keyshawn Greene
- Another good Monday column from Derek Peterson who hits on football, recruiting and basketball in one fell swoop.
Today’s Song of Today
Brandon is the Managing Editor for Hail Varsity and has covered Nebraska athletics for the magazine and web since 2012, Hail Varsity’s first season on the scene. His sports writing has also been featured by Fox Sports, The Guardian and CBS Sports.
