How many of these boxers will fight into their 50s?

[Pigeons]

Bernard Hopkins (currently 51): Last fight was at 49 on November 14, 2014
James Toney (currently 47): Last fight was at 46 on August 8, 2015
Antonio Tarver (currently 47): Last fight was at 46 on August 14, 2015
Roy Jones Jr. (currently 47): Last fight was at 47 on March 20, 2016
Shane Mosley (currently 44): Last fight was at 44 on December 17, 2015
Shannon Briggs (currently 44): Last fight was at 44 on May 21, 2016

My picks are Hopkins, Tarver, and RJJ.

Update #1:
Bernard Hopkins fights at 51 on December 17, 2016.