A lot of fighters have weaknesses that are obvious to us as fans, but sometimes those weaknesses are never fixed.
Thomas Almeida-Defense, being a slow starter
Conor Mcgregor-Cardio
Masvidal-Fighting with urgency,(granted Wonderboy is a tough opponent, but he was far too passive)
Aldo/Barao-Cardio/weight cutting
Cowboy being a slow starter, he got destroyed by other notoriously slow starter Masvidal
Damian Maia-Conditioning, he was getting beatdown by Covington in the third round
Anyone who gets subbed by Oleksiy Oliynyk-he's small, slow, and totally open to getting hit, pick him apart at range!