474 winning % (Marlins at 460, Padres at 465, Rockies at 464)
11,279 losses (#1)
2 WS (Rockies, Padres have 0)
They have a good claim at worst franchise of all time, but the 2 World Series titles kind of turns it around. Over the past 50 years, they've been a fairly good franchise. Their distant past is what drags them down. That's history pal!
Marlins are pathetic, but have a few rings. Rockies and Padres have similar W/L and neither have won a World Series. Rockies have Rocktober. Padres beat the Cubbies for an episode of Punky Brewster. I believe the worst franchise of all time is the Padres. Their 5th highest career bWAR guy is Andy Ashby at 22.6 bWAR (he wouldn't be top 5 for the Rockies who have a 25 year disadvantage).