A friendship between a white person and a black person which is so awesome that experts can't explain it.
Notable examples include J.D. and Turk from Scrubs, Shawn and Gus from Psych,
Riggs and
Murtagh from the
Lethal Weapon series.
Daniel: Henry
my black friend you are so awesome
Henry: And
you too,
my white friend Daniel
Daniel: We are so awesome. Like a chessboard!