1. Cain Velasquez
You cannot fully be considered the best heavyweight in the world without having defeated Cain Velasquez.
The problem with this is that Cain Velasquez fights so infrequently, and pulls out of fights more often than anyone (with Jose Aldo being a possible exception). Not only that but sometimes Cain fights so poorly compared to how he is capable, that even beating him doesn’t guarantee the critics will even believe you are a better fighter than him.
Take Werdum, he beat Cain decisively at UFC 188 and everyone said “Cain wasn’t used to the altitude” and an immediate rematch was to be scheduled, only injuries prevented it from taking place.
Many consider Cain to be in the conversation with Werdum and Emelianenko as the greatest heavyweight of all time, but he is in his prime fighting years and has only had 3 bouts in 4 years.
For Cain to be considered the greatest heavyweight he needs to regain his championship for a record 3rd time. And for Stipe to be considered the greatest heavyweight currently, he has to beat Cain Velasquez.
