For reasons related to its past being far more glorious than its present or future, few sports relate back to their history more than boxing.
The serious sports fan will probably have a working knowledge of the careers of legends and former world heavyweight champions such as Jack Dempsey, Rocky Marciano and Muhammad Ali.
That trio, by the way, all had one thing in common.
All three were considered linear champions, which is to say they beat the man who beat the man who...
On Saturday in Los Angeles, Vitali Klitschko beat Corrie Sanders to claim the WBC heavyweight title - the fourth time a world heavyweight title has been fought for in a month.
But in the eyes of boxing's experts and historians, this fight was the one that decided who was the man to succeed Lennox Lewis, who vacated the WBC belt earlier this year after announcing his retirement.
American boxing magazine The Ring - which bills itself as The Bible of Boxing - believes that when a linear title is vacated it can be filled by the winner of a fight featuring the number one (Klitschko) and three (Sanders) contenders.
The linear title has always been an important part of the way the world heavyweight championship was perceived. For example:
In 1988, Michael Spinks, who did not hold a world title, was considered the linear champion because he had beaten Larry Holmes twice. After 91 brutal seconds of combat with Mike Tyson - who everyone knew was better - Spinks lost his linear crown.
In 1971, Joe Frazier had been crowned heavyweight champion of the world after emerging victorious from a tournament Muhammad Ali, the former champ, had not lost - he simply had been denied his right to fight after refusing to partake in the Vietnam war. Eventually, Ali was given his licence back and when Frazier beat him convincingly in a 15-round fight regarded as one of the best in history, the Philadelphian was finally considered the linear champ.
After Joe Louis retired from boxing in the mid-1940s (he would come back, of course), Ezzard Charles beat a number of contenders to establish himself as the best heavyweight in the world. But he had to beat a faded Louis in 1950 to be considered the linear champion.
Sometimes being the linear champion is not enough - Lennox Lewis knows that all too well.
Lewis was ringside at the Klitschko v Sanders fight
Britain's finest ever heavyweight became the linear champion the night he beat American Shannon Briggs in 1997.
The problem was Briggs was not very good - while Evander Holyfield, who held two versions of the world title and held a couple of wins over Tyson, was regarded as the best in the division.
Even when Lewis beat Holyfield in November 1999, his status as the very best in the world was disputed because he had never faced Tyson.
It was only once he beat Tyson in 2002 that Lewis was recognised as the undisputed world champion.
Let that be a warning to Klitschko, who has already demanded a rematch - only if Lewis stays retired will he be considered the man...