Cheezborger cheezborger! For the second time this year Notre Dame benefited considerably from the bye week, both in the rankings (moved up in both polls last time and in the Coaches Poll this time) and in advanced stats metrics. SP+ in particular took a much kinder view of the Irish this week, presumably off the strength of respectable performances by past opponents – most notably USC, who thumped Arizona 41-14, and Virginia, who destroyed Duke 48-14.

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 8 Update – SP+

Post-Week 8 Update – FPI

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 figure at the end of the Stanford row reflects our probability of winning out (in this case, having 11 wins through 12 games). FPI and SP+ obviously have very different pictures of Notre Dame, but the main takeaway here is that the odds of winning out went up in both metrics this week.

Week by Week Game Trends – SP+

Week by Week Game Trends – FPI

Note that I only just started tracking FPI and I can’t get past data for it, which is why this has so much less information than the SP+ graphic.

Other Nuggets

  • Tackling the “Big Three”: With the USC game behind us, SP+ has a Michigan/Stanford split finish as the most likely outcome of the Big Three at 49%, while FPI’s most probable outcome is a sweep at 52%.
  • Taking care of business: Notre Dame’s expected win total per SP+ jumped from 9.15 to 9.41, while FPI’s inched upwards from 10.03 to 10.10. If the Irish win all games in which SP+ heavily favors them (70% or higher win probability) that expectation moves up to 10.41, while in FPI it moves to 10.62. The astute among you may have noticed that the fractional segment there is equivalent to the models’ respective projections for the Michigan game, as Notre Dame is a prohibitive favorite in both models in every other remaining game.
  • Movers and shakers:
    • It’s been quite the wild ride for the SP+ win probability against Michigan.
      • It steadily climbed a total of 18 points from preseason to Week 4, when Georgia held off Notre Dame and Wisconsin destroyed Michigan.
      • It then dropped all the way back to the preseason number the next week, when Michigan hammered Rutgers and Notre Dame (eventually) strangled Virginia.
      • Then it bounced back 6 points the next week, when the Irish hammered Bowling Green and Michigan struggled with Iowa. Turnabout is fair play.
      • Then it dropped almost 14 points again when Michigan pulled away from Illinois (who SP+ thinks is terrible) and the Irish staved off USC (who SP+ thinks is decent).
      • Finally, it jumped almost five points again when Notre Dame was idle and Michigan lost to Penn State. I hope you like roller coasters.
    • The only other real item of note is that the win probabilities against Duke and Stanford went up significantly in both models. Which tends to happen when you play as badly as they do – Duke’s result was noted above, and Stanford lost 34-16 to a really bad UCLA team.