DC and others have said that if Volk wins it will be the biggest upset in UFC history. IMHO If Volk beats Islam it will not only be the biggest upset but it will be the absolute biggest victory in UFC history. No one else has ever been actively defending a belt and then gone up and fought a guy THAT much bigger than them and who is THAT dominant of a grappler. Islam is a welterweight cutting a shit load just to make lightweight (just like khabib did) and also happens to be the best wrestler in the division. That is a combination of attributes that presents such a challenge that you just wouldn’t see anyone else attempt this in the modern era.
The way I see it only three other wins compare on paper to what Volk is attempting here. Conors win over Alvarez, DC’s win over Stipe AND BJ Penns win over Matt Hughes. (maybe Couture over Tim Sylvia is Sylvia was higher level opponent)
Now im gonna break down why Volks attempt here is a bigger deal than these three other wins.
When Conor moved up he had never defended the title at featherweight (anyone else would of been forced to vacate before the alvarez fight) and was a natural lightweight who cut a shit load to make featherweight in the first place (with the help of IVs). He more or less became the featherweight champion by fighting guys significantly smaller than himself. He also went up to lw at a time that the champion was a sloppy brawler with a reach disadvantage which was practially the perfect matchup for Conor.
Cormiers run at lhw/hw was pretty much the same story. Im not saying he weight bullied the LHW division quite like conor did at featherweight but he did literally cheat to make weight at least once. More importantly in DCs case, the fact is he was never the legit best guy at LHW, Jones was. His win over Stipe was a big deal obviously as Stipe is legit as fuck, but he wasn’t a significantly larger fighter than cormier and was not the better grappler of the two. Also Cormier poked stipes eye bad just before the KO but some will argue that that isn’t relevant (i think it is).
Volk is not weight bullying at featherwight. In fact he has looked undersized even at FW. Although he has fought at MW, WW and LW, he is clearly a natural FW. So right there he is doing something far more impressive by moving to LW than conor or DC did when they moved back up to their natural weights. He’s also doing it against a guy who is not just bigger, but a guy who is big even for LW.
I think the closest comparable win would be BJ Penns win against Matt Hughes. BJ was moving up against a guy that was way bigger and stronger, and was one of the most dominant wrestlers in UFC history. The chips were stacked against him in a way that is very similar to what Volk is facing in this fight with Islam. The reason why i think Volks win would be bigger is simply the fact that BJ wasn’t the undisputed champ of the lower weight class at the time of the fight with Hughes.
So all in all if you take into account the fact that Volk is indisputably the best in the world at FW with several title defences while actually being a natural FW (conor never could of been FW champ wothout IVs and never defended) and if you take into account the momentousness of what he is achieving on paper, plus the literal challenge that he is facing in Islam Machachev, then if he wins it will be the single greatest, biggest, most momentous victory in all of UFC history bar none.
Obviously this is a big IF though and the most likely outcome is a submission victory for Islam, but Volk has a chance.