Earlier this summer, I kicked off my annual simulation-based preview of the upcoming college football season. So far, we have analyzed the accuracy of the preseason rankings, looked back at the 2022 season results and conducted a deep dive of the Michigan State Spartans' schedule.
In today's installment, it is time to look more specifically at the overall Big Ten race, including the impact of the schedule, simulation results and a few predictions.
Strength of Schedule
The concept of strength of schedule is an interesting topic in and of itself. Many people have made attempts to quantity strength of schedule over the years, but most these methods seem dubious, at best. These calculations often utilize winning percentages from the previous season, which only tells us something very basic.
I have developed my own method to measure strength of schedule that is substantially more rigorous and useful. The idea is to calculate the number of expected wins for a borderline top-25 team playing any arbitrary schedule. Expected wins are calculated using my power rankings and the resulting projected point spreads.
I applied this method to all 133 FBS teams in 2023 and calculated the strength of each team's full schedule and conference schedule. Figure 1 below shows the results of this calculation for all 14 Big Ten teams with the national ranking of schedule difficulty shown on each bar.
One of the main advantages of my method is that each team's strength of schedule has a quantifiable meaning (expected wins). So, when the Wisconsin strength of schedule (8.8 wins) is compared to the Michigan State strength of schedule (7.3 wins) we can see immediately that Badgers have a 1.5-game advantage over the Spartans based on schedule alone.
Figure 1 shows that there are two main groupings of Big Ten teams in 2023: teams with schedules in the top-25 of difficulty and teams outside of the top-40 in difficulty. The Spartans' schedule grades out as the sixth-most difficult schedule in the nation. The only teams with tougher schedules are a quintet of SEC teams: Florida, Ole Miss, Alabama, South Carolina and Texas A&M.
Five other Big Ten teams have relatively challenging schedules overall: Indiana, Rutgers, Minnesota, Ohio State and Purdue. The remainder of the conference, however, grades out near the very bottom of Power Five teams in schedule strength. Notably, Michigan, Iowa and Wisconsin all rank in the bottom-15 of Power Five schedule strength. For reference, the Power Five team with the weakest overall schedule is Boston College at No. 69 with 9.2 wins.
For the purposes of the Big Ten race, the conference schedule difficulty is a more useful value to calculate. Figure 2 below summarizes those values.
Once again, this analysis provides a clear and quantitative summary of the actual strength of each team's schedule. We see here that Rutgers (4.7 wins) has the most difficult conference schedule, while Wisconsin (6.2 wins) has the easiest schedule by 1.5 games out of nine total.
Overall, eight of the 14 teams have a schedule strength that is just a few tenths of a win stronger or weaker than the conference average (5.46 wins). Michigan State, with the third-most difficult conference schedule (4.9 wins), joins Indiana and Rutgers in a cluster of teams with notably tough slates. Meanwhile, Wisconsin, Iowa and Illinois all have notably easier conference schedules relative to the average.
Big Ten Win Distributions and Odds
In the deep dive of the Spartans' schedule, I summarized the odds for Michigan State to win anywhere from zero to all 12 games on the schedule. These odds were calculated using the preseason rankings, the schedule and the historical uncertainty in the preseason rankings. Table 1 below shows the same calculation for all 14 Big Ten teams.