Totally depends on the destination. South Africa rolled down pretty deep. Nice, stayed pretty close to the top. I never had the chance to race a NZ qualifier, so sad face on that. But, I will let you know in 2022.

Edit: Should have added that my Nice qualifier did not roll into the 20s as far as I can remember, and most AGs did not roll past 10. By contrast, South Africa rolled into the 20s for many AGs, and a few rolled almost to 50th. I did not take an SA slot, because I did not want to do a trip to that destination. But, I will absolutely take an NZ slot if I have a chance.

Depends on a lot more than the destination. Here are the factors in my mind.

1. Roll downs for overseas 70.3 WC go much deeper than U.S. 70.3 WC, but ...
2. Popular destination roll downs don't go as deep and ...
3. Early season race roll downs generally don't go as deep; but season end qualifiers can go very deep no matter the destination.
4. Senior age group roll downs don't go as deep as younger age groups, especially M55+ with more income
5. Men's roll downs don't go as deep as women's [in general]. After they introduced a separate women's race, IM has given extra slots to top performing women separate from roll-down qualifiers.

Even saying that, it can be a crap shoot depending on the particular qualifying race you choose.

Check this - https://forum.slowtwitch.com/...s_P7027721/#p7027721

The are some data from U.S. events. Roll downs to 20+ places are very rare.
Generally, you needed to be in the top 10 to be able to get the slot.

I raced Santa Cruz 70.3 2019 and there were almost no big roll downs.