Dubois is slow, hittable and far from unhurtable, could Fitz and his r3tarded level of power have had any success?
I say Dubois by stoppage, the difference in size and power between the two is too much. Dubois probably would have taken Fitzsimmons' blows, but I think Bob wouldn't have taken Dubois' blows.
Fitzsimmons by knockout. Dubois stands square a lot, is a big target, is a sucker for straight rights and lefts, and goes to pieces when he gets rocked. I have a hard time seeing Dubois lasting very long with Fitzsimmons.