The Irish used a relentless offensive game plan and a calculated defensive game plan to hold off a talented rival in a marquee matchup. SP+ didn’t view that performance so kindly, largely because patient offense and bend-but-don’t-break defense tend to work counter to the metrics that SP+ considers important. Could the Notre Dame offense have been more explosive? Maybe. Could the defense have been more aggressive and forced more Trojan errors? Possibly. At the end of the day, though, Chip Long’s George Foreman act and Clark Lea’s Floyd Mayweather act worked perfectly together and the Irish came away with a hard-fought win. Hard to argue with that. It’s also worth noting that Brian Kelly has now won three straight against USC and is 7-3 overall against them, which is the best mark for an Irish head coach since Lou Holtz closed out a 9-1-1 career against them.

Recapping the methodology again: These aren’t actual SP+ win probabilities, as SP+ creator Bill Connelly doesn’t publish those regularly after his preseason previews. We used a slightly tweaked version of the formula that the Reddit guy reverse-engineered to get close to published probabilities. That formula does some probability magic on the differential in SP+ rating for the two teams (with a bump for home field), and voilà.

Post-Week 7 Update

As you move down each column, you find the probability of Notre Dame owning that many wins at that point of the schedule. In the first row, you can see that the probability of owning 0 wins through week 1 is 0% and one win is 100%, since we already won. Same for the New Mexico row, and so on. In the last row, we’re tracking how much the probability of each win total has changed from the previous week. This is largely a function of our own outcomes, the quality of play that led to those outcomes, and SP+’s changing perceptions of our opponents.

The 8.9% figure at the end of the Stanford row reflects our probability of having 11 wins through 12 games – in other words, that’s our probability of winning out. That dropped a lot from last week based on Notre Dame’s own SP+ rating dropping rather precipitously. 9-3 is back to SP+’s most likely outcome, at 35.1%; very interesting, as I think at this point anything less than 11-1 would disappoint a very large portion of the fan base.

Week by Week Game Trends

Other Nuggets

  • Tackling the “Big Three”: It felt a little silly to redefine the “Big Three” again with the win over USC in the books – I mean, do any of you consider Duke a big game? How about Navy? So I’ll just track Michigan and Stanford at this point. Not surprisingly, given the sharp drop in the win probability against Michigan, some kind of split with Michigan and Stanford is the current most likely outcome, at 56.1%. A sweep is next at 26.3%, while endless sadness trails at 17.5%.
  • Taking care of business: Notre Dame’s expected win total dipped down again from 9.33 wins to 9.15 wins. If the Irish win all games in which SP+ heavily favors them (70% or higher win probability) that expectation scooches up to 10.03 wins, which is down from 10.16 last week. Michigan and Duke are the only non-heavy-Irish-favorite games remaining.
  • Movers and shakers: Highlighting just the notable movers…
    • I just don’t get the Michigan move, a whopping 13.5 point drop in win probability. They looked pretty bad for sizable stretches against a below-average Illinois team. But, again, they’ve figured out how to game the SP+ system, plus this year the conference adjustments are very friendly to Big Ten teams. Let’s see what happens this week when they travel to Happy Valley.
    • I’m not going to react to too much else here, because I think a lot of it comes from a strategic game plan against USC that doesn’t play to SP+’s preferences, as noted above. The one other thing I would highlight, though, is the Navy win probability dropping 9.4 points after they dismantled Tulsa 45-17. I’m not sold on them yet, but there’s a much better chance today than there was preseason that they might provide some resistance.