Quiz: How well do you know the lineal heavyweight champions?
As representatives from Anthony Joshua meet their opposite numbers in the Deontay Wilder camp, we could be just one fight away from getting another lineal heavyweight champion of the world.
Twelve rounds to decide who will be undisputed as the finest heavyweight boxer of them all.
There have been a series of lineal heavyweight champions over the years, but how well do you know them?
See if you can decipher who these lineal world champions are from our clues: