Pacquiao went from 105 pounds to 145. Walker went from 140 pounds to 175, but also fought heavyweights who were nearly 200 pounds. Pacquiao beat Marco Antonio Barrera, Erik Morales, Juan Manuel Marquez, Oscar Larios, Oscar de la Hoya, Ricky Hatton, Miguel Cotto and Joshua Clottey. Walker beat Mike McTigue, Lew Tendler, Tiger Flowers, Paul Berlenbach, Johnny Risko, Maxie Rosembloom, King Levinsky and Paolino Uzcudun. Who is greater?
You mentioned only a few of Walkers great wins, but all of Pac's. Walker is clearly the greater fighter. It's not even close. Walker is a lock top ten P4P all time great, I can see him as high as five. Pacquiao is in somewhere between 20 and 40.
Just a few quick points. Though pac is a bona fide certified atg,i think too much is being made of the raw 'statistics' of his winning titles from 112 to 147. Though this is a phenomenal achievement,we must factor in the fact of the 24 hour weigh in and the use of IV drips to rehydrate fighters nowadays,as a reason why some fighters can compete in weights much lower than they really are 'naturally'. Fighters can also win titles in 'fragmented fashion' thus giving almost anybody a 'world' title even at a very young age or against poor opposition. Janny is right,lets wait till he has retired (or even until its proved he can beat money may') to pronounce his true or final status.
Similar in many ways, both weight hopping multi division champs, both had problems with slicker more skilled boxers, both got the benefit of controversal decisions. Neither were particularly dominant in any division they campaigned at Walker has more clear losses in his prime, but Pacquaio has being protected from the slicker boxers and would likely have more losses himself otherwise Visually Pacquaio looks to be the more impressive fighter at his prime weight If Pac does beat all at WW, he clearly rates above Walker, as that would make him a dominant WW, something Walker never managed at any weight