Top 10 lightweight easily, somewhere around 6 or 7 Top 30 welterweight Top 40 p4p Deserves major credit for unifying lightweight title, beating Azumah Nelson and "beating" Chavez when all of those feats really meant something. Not a guy that I found much fun to watch, but deserves respect for his achievements. I've seen him ranked in top 20 or 30 p4p but I think that's too high overall.
I guess at 135 Top10 is fair, maybe higher even. Not at all at 140. Maybe Top20 at ww, barely. Top30 would be more alright considering the depth of that division. Wouldn't rate him at 154. P4p for the last 30 I think he'd be Top5 (with Pac, Mayweather, RJJ and Hopkins being the others). All-Time, maybe Top30-50ish? He has too little fights to be higher IMO.
He beat Nelson at 135 a division Nelson was clearly too small for and accomplished absolutely nothing at. Ditto for Chavez at 147 which was a draw, that he should of won on the cards but also could have easily lost via DQ. Why does that deserve major credit?
Nelson had only one defeat at that point (8 years previously) and had dominated at feather and super feather for over half a decade. Chavez was 89-0 and universally regarded as p4p no 1 in the world. Whitaker was not naturally much bigger than Chavez and was above his own natural weight class at welter anyway so I don't really think size was a major factor.
Pernell Whitaker wasn't legitimately beaten until 1999 at `147 by a great Welterweight Felix Trinidad. While guys like Holyfield and Barrera were losing fights at or near their prime. He may not have been as fun to watch for some fans but he was greater than both of those guys. At the peak of Sweet Pea`s career he rarely lost a round.
At 135, I put him in the top three along with Duran and Benny Leonard. He was that good. At 147 I think Whitaker can just about hit the 'great' category, but obviously not in the same class as he was as a Lightweight. Haven't pondered a 147 lb order of things for a while, but off the top of my head I'd probably have him somewhere around the #15 or #16 mark. With regards to 140 and 154, he only ever made pit stops in each division, but safe to say he could beat basically anyone who ever held a Light-Welter belt, while in the latter class he could beat the decent champions, but not the ones from the top bracket, albeit he probably wouldn't be disgraced against any of them. Roll that all together, then add the quality of his wins / performances across many weights and almost ten years when facing the likes of Ramirez, Vasquez, Haugen, Chavez, Nazario, McGirt, Nelson etc., and finally factor in how utterly dominant (or at least almost impossible to definitely get the better of) he was until eventually facing a peak, much bigger and fearsome-punching Tito when a drug-addled, inactive 35 year old....And I reckon you've got yourself an all-time top fifteen pound for pounder.
Holyfield beat some great fighters but he also lost to guys like Michael Moorer a good but not great fighter. Really nothing like that on Whitaker`s resume unless you put stock in robberies like Ramirez. Not to mention losing two out of three to Bowe.
Having a cruiserweight unify and then move up to heavyweight and be the most important champion of his decade is territory only charted by Holyfield, against top opposition nonetheless. Pacquiao, Mayweather, Armstrong and Duran come to mind as guys who put together better resumes moving up from 135 or less to have success at 147/154 or in some cases 160. Others like Chavez, Arguello, Oscar, and Marquez are neck and neck with him or close to it.
They were elite fighters at their weights but there is a discount when you fight guys above their class especially in weight classes they have absolutely zero accomplishments in. Nelson doesn't have a single win above 130 and Chavez best win above 140 is Joey Gamache for God's sake. What also hurts is that the win vs Nelson while completely in control(9-3 or 8-4 fight) was something less than dominant never hurting Nelson or making him quit. And the Chavez fight was obviously less than dominant.
I understand the weight argument but would you apply the same rationale to, say, Aaron Pryor's win over Alexis Arguello? Just interested. Dominance of performance is a factor but I'm not sure Whitaker deserves to be penalised for not stopping Nelson.