That's because Spence keeps facing leprechauns from lower divisions and scrubs, whereas Khan is a certified warrior which is something he has proven time and time again. And Khan was fighting with a broken right hand for a decade which has now been surgically repaired. You can't put your full weight into a punch if you don't have your legs beneath you. Benavidez's leg was so messed up after he got shot in it it was almost as bad as him having a prosthetic one. Garcia knocked Khan out with a throat punch, you do realize that if you deprive someone of oxygen they're either going to pass out or die don't you?
What did Prescott knock Khan out with? Excuses, excuses and more excuses. When Khan loses to Crawford he will become a "bum" for you and the haters and you will move on to the next person who will "beat Crawford." Crawford is here to stay and he will be here for a long while. Deal with it and quit trying to find excuses for why he continues to win.
I can't pretend this fight isn't interesting. Khan's BoxRec has LEGIT names up and down that list and nobody has ever outboxed him before. I have no doubt that Crawford will separate him from his senses at some point, but I am damn interested to see if Khan lifts the clear majority of rounds off him like he's done to every single other fighter he's fought.
I wouldn't be surprised in the least of Khan beats him. Khan has a very special set of skills. You gotta crack that chin, crawford can but he has to catch him. Depends how perfectly Khan fights but pretty sure he takes a few rounds from Crawford if he doesnt get ktfo early.