Big 10 Conference Preview: Simulating the Season

The 2021 Big Ten season kicks off this Saturday with Nebraska vs. Illinois at 1 p.m. Eastern. This will be the first Big 10 game of the year, and the first game in over a year that will resemble what we are used to imagining Big 10 football to look like as the Big 10 did not allow fans last season.

Using our Elo ratings, which serve as a measure of each team’s strength and update after each game, we simulated the upcoming college football season 10,000 times. This was done for every matchup for every team across the sport, but this article will just focus on the results of the Big 10 teams. Using our Elo ratings, we simulate the outcome of each game over and over as we progress through 10,000 hypothetical seasons. At the end of these 10,000 seasons, we take some averages and calculate some stats to see how many games each team is likely to win on average, their probability of going undefeated, and more.

One particularly interesting thing about our season simulations is that they are run “hot.” This means that as teams win and lose games in the simulated seasons, their Elo ratings change just as they would in real life. The reason for doing this is because it adds in some much needed variation to the simulations and allows teams to go on a run (or keep losing), increasing their Elo rating (or decreasing it) and thereby increasing (or decreasing) their probability of winning future games. It’s also a better reflection of real life. Nebraska does not play at the same level each and every game, and we want to adjust their Elo rating in the simulated seasons just as we do when the real games are played.

At this point, since it’s preseason, no games have been played. When the season starts we can continue to run our season simulations and only simulate the remaining games, taking the ones that have already been played into consideration with their actual result, and starting each season with every team’s current Elo rating.

One more note about the simulation before we get into the results. Our program just simulates the regular season games, not the playoffs or conference championship games. Simulating conference championship games is something that I hope to add in the future, but the playoff will likely not be added for a long time as picking the top four is not governed by a set of rules. We can (and hopefully will soon!) write the rules into code for how the two teams get chosen to play in each conference championship game. Once the top four is set at the end of the season, though, we can simulate out those games too.

Okay, so what does the sim say about the 2021 season ahead?

Your eyes are probably drawn to the orange row right away, and for good reason: it’s the row that is home to the winner of the last four Big 10 championships – Ohio State. Ohio State is once again predicted to the be the best team in the Big 10 by a large margin. They win an average of just over 11 games in our simulations and have a 45% chance of going undefeated this season. Their next closest competitor in the East is Indiana, who are projected to win 7.7 games. Penn State sits third in the Big 10 and are projected to win 7.5 games.

If you look at the undefeated probability column, you’ll see lots of teams have a 0% chance of going undefeated. One thing I want to note here is that they don’t have actually a 0% chance of going undefeated (there is a chance every team goes undefeated – it is not certain they won’t go undefeated until they really lose a game), but rather they went undefeated 0 times in the 10,000 seasons we simulated. More realistically, they have a 0.000001% chance of going undefeated (or something like that). But 0% is a pretty good estimate.

Now let’s look at the West side, which is always a closer division. Northwestern and Iowa are the two frontrunners in the West division. They each are projected to win an average of 8.7 games and have about a 1% chance of going through the regular season undefeated. Interestingly, Iowa’s 95% confidence interval for how many games we think they will win is slightly larger than Northwestern’s, indicating more uncertainty about how their season will turn out. Wisconsin is a close third in the West as they are projected to win 8 games. Wisconsin’s projected win total would likely be higher, but they play Penn State, Michigan, and Notre Dame this year in addition to their regular Big 10 West opponents.

The Big 10 looks like it will continue to run through Ohio State this year, and that is probably what most would expect when clicking to read this article. That said, the Big 10 West does look wide open this season with multiple teams battling for the chance to make the Big 10 championship game.

We will periodically run the season sim throughout the year as games are played and update our predictions, so be sure to stop back on Staturdays soon to see how the forecast changes.


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