User blog comment:SlatBH/Route to Endurance Legends/@comment-43864192-20191124175809

Just unlocked CSF, and there are a few things that can now be said, as of Update 7.6 and possibly 8.0 as well:

1) Unlike all other non-final main Career (Non-Exclusive Road Collection from 8.0 onwards) Series in a certain group, Endurance Legends is unlocked before the final tier gets unlocked; one needs 48 trophies to unlock the final tier whereas Endurance Legends is unlocked at 37 trophies (NOT 36, as per CSF progression) at Tier 17. Thus, all progress from Tier 17 onwards is irrelevant towards unlocking Endurance Legends.

2) As we have that: i) A Time Trial is every 5 Tiers (5, 10, 15, 20), ii) All non-TT tiers consist of a Cup and two non-Cup events and iii) There are no jumps in tiers of 4 or more trophies, we need a total of 37 trophies out of (16-3)*3=39 trophies, thus two cups can be skipped, leaving us with a PR requirement of 116.0 (Req. PR for Cup in Tier 13).

So, all that remains is to check the optimal upgrade strategy and to check whether Yas Marina would change things here. I'll update this comment as per the F1 update, although I don't expect things to change here for 8.0.