Most fishermen have heard the claim that, pound for pound, bluegill outpull bass. There is also the claim that if a bluegill got to five pounds no tackle would hold them. I have to disagree. I think people feel like bluegill pull harder because they catch them on light tackle compared to bass. I have caught one-pound bluegill and one-pound bass back-to-back on ultralight tackle several times and I think bass are stronger than bluegill. And one fisheries biologist I interviewed agrees.
picture (c) Ronnie Garrison

Comments
Bass are more muscular than bluegills so I would assume the bass would pull harder even if they weighed the same.
Given a bass and a bluegill of the same weight on the same tackle I doubt anyone could notice a difference.
Pound for pound the bass has a greater pulling power over the bluegill. I have also caught bluegill and bass on the same equipment. The bluegill never had a chance…
I also have caught bass and bluegill on the same tackle and the bass almost broke my line every single time. So in my opinion the bass pulls a lot harder, but that’s not to say that really big bluegill don’t pull hard. I caught a nearly three pound bluegill on ultralight tackle with 4# line and almost broke my rod.
In my opinion bass are a lot more stronger and a lot more fun to catch.