lets just say of their weight classes so this post dont get hijacked about goat talk.... Great fighters are all over the place. Its not being great that can allow you to become an undefeated goat. There are simply too many wild cards in combat sports and if you fight long enough you will get cracked. IMHO one thing YOU ABSOULTLEY must have if you want to be an undefeated goat contender, you must have a GOD LEVEL chin. yes you must also have so many other things. However without that chin at some point your going out. Look at nearly everyone. If you look closer you will see Justin actually crushed khabib with a major shot, a few of them. It didnt even phase him, not even a little bit. Just like when Michael johnson hit him. Nothing lol. These are shots that KO other people stiff. Same thing with floyd in boxing, When i saw him eat a haymaker from sugar shane it became apparent he wasnt going to lose. Its possible to be ONE OF the goats with a normal chin. however to really get to zero loses....you MUST have a granite chin.