Fox decided last season to ignore the live+same day ratings (those who watched a show on the day of original broadcast) and to focus on the ratings that came from viewers watching on catch-up (which explains why flop Scream Queens eked its way to a second season). The Simpsons has only appeared in the top 25 broadcast show lists for live+3 catchup when the episodes have been NFL boosted so far this season.
The first NFL-boosted episode of the season, “Friends and Family” had 2.6 on its original airing, and after three days of catch-up, gained 0.3 and 12% versus its Live + Same Day rating, to 2.9, ranking 13th of the top 25 broadcast shows in Live+3 18-49s of the week ending October 2nd. “Treehouse of Horror XVIII” was boosted also, gaining 0.4 and 13% versus its live+same day rating to 3.4, ranking 8th in the broadcast shows of the week; this episode seemed to have had the “Treehouse of Horror” aspect work its way into the higher viewership as well, and to a lesser extent the fact it was the 600th episode (although the 500th did see an increase due to its landmark status).
In both cases, they were the second most-watched shows of the week in 18-49 ratings for FOX, behind Empire, which had 5.1 and 4.6 respectively. Outside of football-inflated episodes, The Simpsons usually is a non-appearance in the list, and probably only gains a tenth or two in catch-up, since Family Guy usually sneaks into the list with a similar live+same day rating.
The next football-aided episode isn’t for another three weeks, so we probably won’t be seeing The Simpsons in the list again until the episode in which they take Grampa to Cuba – are they sure that’s a good idea?