Basically using cross breeding to resurrect a bulldog breed from before inbreeding ruined them.
“The result was an athletic breed that looks similar to the bulldogs of 1820, but with a friendly temperament, fewer health issues, and with longevity reaching into the teens. U.S. researchers have said the Olde English Bulldogge is a “viable candidate” as an outcross on which to rebuild the Bulldog; a breed that genetic studies have suggested is so inbred that it “cannot be returned to health without an infusion of new bloodlines.”[4]”