We are happy to turn on our predictions for every Illinois football game, based on a mathematical model for team strength, as determined by offense (number of points scored vs. expected points scored) and defense (number of points given up vs. expected number of points given up).
We have also developed an ad hoc report that will reveal all the games played by Illinois teams for which our model failed. Here is a summary of our algorithm’s performance in Week 4:
- Games played between two Illinois teams: 283
- Games called correctly by our algorithm: 230 (81.3%)
- Games we called incorrectly: 53 (18.7%)
A performance greater than 80 percent in Week 4 is pretty good. We’ll see if it improves as the season moves forward and teams get into their groove.
The 53 games we missed deserve a closer look. Our ad hoc report is set to consider games played within the last seven days, so during the weekend, it may get a little wonky. It will settle down by Monday morning, though, as games that were played during the previous weekend fall off the list.
Among the 53 games we missed, 36 were decided by 14 points or less, including 26 decided by a single touchdown (7 points) or less. That means 17 games, or 6 percent, were both missed by the algorithm and decided by comfortable margins.
Games we thought would be close
We generally consider our α statistic to indicate a game between two evenly matched teams when it has a magnitude of less than 10. This was the case in 27 of the 53 games missed by the algorithm, or slightly more than half of the missed games. We take this to reiterate our caution that games with an α magnitude of 10 or less are going to be tough to call.
With α magnitudes of 10–30, we missed 23 games, and 10 were decided by 7 points or less. This is a nebulous region for α, especially early in the season. Once a few more data points are used to adjust the model, this number should decrease.
We called them blow-outs, but they went the other way
We missed only three games where the α magnitude was greater than 30:
- Westminster Christian (1-2) d. Hiawatha (3-0), 24-14
- Lake Forest Academy (0-3) d. DePaul College Prep (2-1), 28-20
- Corliss (1-2) d. Hope (2-1), 22-16
Last year, we had a few surprises every week as well. As often happens in high school sports, Westminster Christian just turned their game up a notch against the undefeated team from Hiawatha.
A report in the Daily Herald credited Westminster’s offensive line with a game-winning performance, especially Zach Aters, whom coach John Davis called a “man-child” because of the holes he opened up for running back Xavier Brown. The back rushed for 176 yards in the game, including two touchdowns.
More than likely, the other games had similarly stepped-up performances.
