It's has to be one or it's going to get too confusing, as in, then everyone will do two burgers way different. One protein and you can make a double burger or two dressed differently however, using proteins (hint). 

hot stuff said:I'd do a dual with someone with a mixed meat burger: ground beef plus one or more other ground meats integrated with the beef. Who wants to rumble?
The Hot Pepper said:veggie
Ozzy2001
dragonsfire
crab
JoynersHotPeppers
tctenten
gator
Student of Spice
CheriLBW
The Hot Pepper said:veggie
Ozzy2001
dragonsfire
crab
JoynersHotPeppers
tctenten
gator
Student of Spice
CheriLBW
beef blend
grantmichaels
hot stuff
tctenten said:http://thehotpepper.com/topic/36673-the-next-throwdown-is/?p=1455436
I think he is in…at least that is how I read it.