I can think of one modern example.. Teofimo Lopez didn't put a foot wrong vs P4p #1 Lomachenko when they fought, but looked rubbish Kambosos. James Toney has looked absolutely unstoppable, then garbage his next fight. Roberto Duran went from a menance to an unbothered fighter.
Teofimo is not inconsistent. He’s never not in the gym, never not in shape, never misses weight. He’s just a hypejob because people refuse to admit Lomachenko was injured and handed him rounds.
Teofimo Lopez, Tyson Fury, Evander Holyfield, Jermell Charlo, Ryan Garcia, Roberto Duran, Joseph Parker
Fury is a good example. Arguably lost to 0 - 0 Ngannou (who wasn't even a good technical boxer in MMA, he was just very powerful) and then gave Usyk one of his toughest fights right after.
Briedis, sometimes looked like an offensive machine, other times he would just coast through a fight.
Winky Wright. There were times he looked extremely pedestrian. Then he would turn in a performance that you make you say "this is why he can't get big fights, it ain't worth the risk".
Didn't exactly watch his entire career but which fights do you think he looked unimpressive? Because the only ones I saw where he looked aight was when he was green (like the Vazquez fight where he was dropped many times) or when he was obv past his prime.
Nah, he clearly fights to the level of his competition to some degree. If Loma only had one working arm he should have pulled out of the fight. Instead he got out hustled and honestly outboxed and lost the fight… Hurt arm or not, that’s what happened. He obviously thought he was fit to win, so…..