I think that the idea of accumulating championship bouts to gain legit credentials is over. There is a new era of fighters just looking for big fights and big payday and its not about gaining respect for fighting titlists and fighting all on comers. The last of this era has to come in the form of Bernard Hopkins, Joe Calzaghe, Felix Trinidad and Roy Jones ... all of whom have gained 20+ championship fights and have had as many as 15 title defenses in 1 single weight class. Roy Jones 23-2 (in world title fights) Bernard Hopkins 20-2-1 1NC Felix Trinidad 20-1 Oscar De La Hoya 24-4 Joe Calzaghe 22-0 Floyd Mayweather 20-0 Julio Cesar Chavez 31-4-2 Pernell Whitaker 19-2-1 Roberto Duran 20 + next in line ... Shane Mosley Manny Pacquiao after that ... its over
I think once Pac and Shane achieve 20 championship fights total, then it will be the end ... I already see it now, the networks are pushing for big fights w/o the emphasis on winning and obtaining championships. Look at Chad Dawson who vacated his titles because Diaconu/Cloud wasn't going to produce more money and now HBO is looking to give him a shot at Pascal which he would've had to fight had he not vacated his title in the first place. Or Bradley vacating the WBC title because he didn't think that Alexander would produce money ... Now these guys are getting multiple championships - but only because they keep vacating titles.
I would also add Cotto to that list !! I don't believe he'll retire any time soon ... and i'm sure that he has another life at junior middleweight ... it would be nice to see him revive his career. There's some easy pickings of Cotto at that weight and i'm sure his more serious threats are closer towards Middleweight.
The meaning of world titles have been so diluted and pointless almost that less emphasis has been placed on them, so it sort of makes sense.
Mosley actually had more than 20 championship bouts. Barrera (still active) is at 24-6 (with a few World Championship bouts after he was stripped). Also, there are some active fighters around the 20 mark: Wonjongkam 20-1-1, Arce 16-3 (a few interim), Montiel 16-2, Calderon 19-0, Sahaprom 14-3-2. And those who could easily reach: Cotto 14-2, Wlad 14-2, Narvaez 16-0-1. But it's not about the titles anymore.