I am basing my accusations of bias on some of the other content on the site. For example the "myths" about pitbulls article where they are all out to murder and maim.
I don't have good statistics to give you because I can't find them. Check the link I posted earlier about how most stats were formulated based off media reports. The media tends to pick something they can sensationalize rather than actual facts. You would think stats from law enforcement agencies would exist that painted a clearer picture, but I haven't been able to locate such a place.
I'll give your second site another shot to make sure my opinion wasn't colored by dogbites.org and report back.
I didn't read any of the editorialized information on the site and really doesn't matter. If they're taking facts and running with them that doesn't mean the facts part is wrong. Let's just take 2015.
2015 U.S. Dog Bite Fatalities - Dog Bite Statistics - DogsBite.org
Note that actually the majority of the data cited in the upper portion of the page is not specific to any breed. Of the 12 data points listed only 4 dealt with dog breed at all.
Moving down to the victims list I independently vetted every other 5th example for accuracy. (I'm not bored enough to check all of them)
Eugene Smith-checked out
Roy Higgenbotham Jr
I'm actually giving this one a pass since as I understand it the owner apparently had a heart attack and Roy, while trying to aid the owner, was attacked by the family pit. One can only assume the dog thought it was protecting it's owner. Truly a sucky story for all involved. (I will add that the dog didn't just attack, it killed the guy, which is no small matter) So next:
Betty Wood-checked out, rottweiler
Brayden Wilson-checked out, and I wish I'd never looked
Annie Williams-checked out
Carmen Reigada-checked out, 3 different mixed breeds involved correctly cited by dogsbite
Anthony Riggs-checked out, rottweiler
Nyjah Espinosa-checked out, "bulldog mix", not cited as pit
As far as I can discern whatever dogsbite.org may or may not feel about pits as a breed their actual data appears to hold up under scrutiny. (at least as far as I've looked) If it wasn't pit related they appear to have no issues making that distinction.
So I'm stuck with my original assertion which is as I type this pits and their immediate analog mixes are wildly overrepresented in dog related fatalities. That we stick to fatalities helps in that such things are going to be much more vetted in the first place. Grey areas are reduced dramatically when someone actually dies. Police get involved, lawyers lined up for criminal and/or civil cases, priority is set on finding the animal(s) involved, etc.