Nobody quite understands the etiquette of an exhibition boxing match, whatever that really means, so nobody knows what to expect when Mike Tyson and Roy Jones Jr step into the ring together.
The legends of American boxing - Tyson is 54 and Jones 51 - will meet on September 12 over eight rounds. They are expected to wear larger than normal gloves and maybe headgear too.
But what happens when the punches start to fly? How do these iconic fighters temper their instincts? Tyson may have picked the wrong rival in Jones Jr.
Mike Tyson: Undisputed Truth
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Four-weight world champion Jones Jr had his 75th and final fight two years ago, then aged 49. He always had trouble saying goodbye to the ring even when it stopped treating him so well.
He retired in his hometown of Pensacola, Florida, at the same arena that hosted his debut in 1989 but, even during the delivery of his retirement speech, he called out UFC star Anderson Silva for one final fight.
Jones Jr fought once in 2018, once in 2017 and twice in 2016 since he was brutally knocked out by Enzo Maccarinelli.
He has fought 23 times since Tyson's final fight in 2005 including against Antonio Tarver, Felix Trinidad, Joe Calzaghe and Bernard Hopkins.
Jones Jr, in his final fights, was nothing like the ring great who won world titles at middleweight and heavyweight. But Tyson was a shadow of himself in defeats to Danny Williams and Kevin McBride before his retirement, a full 15 years ago.
We don't know how seriously the 'fight' will be taken between Tyson and Jones Jr but, if they revert to type, it is the latter who has been competitive far more frequently and recently.
Jones Jr is currently actively training Chris Eubank Jr whose famous father told Sky Sports: "Roy has two things; brains and speed. I only had brains. Roy beat James Toney who, privately for me, is one of the greatest super-middleweights of all time. Toney was a technical boxer but Roy had brains and speed. Roy played with him and I bow to Toney's skill-set."
Tyson has been posting impressive videos of himself training online - the youngest ever heavyweight champion is now 34 years removed from that defining achievement but, over the course of five second clips, looks terrifying.
His great rival Evander Holyfield, whose ear Tyson notoriously bit off, teased a charity bout to Sky Sports: "I don't know, you would have to ask him! I wouldn't ask nobody to do anything they don't want to do. But it's for charity. If we can work something out that works for everybody then it's a win-win-win."
Holyfield is 57 and hasn't been in the ring since 2011. His relationship now with Tyson, despite their in-ring controversies, is respectful and they have made many public appearances together. A charity move-around seemed harmless.
"I really am sorry," Tyson said on his Undisputed Truth documentary. "Me and Holyfield became friends."
Sonny Bill Williams, the rugby player who has had a handful of pro boxing matches, was also touted for Tyson.
A different kettle of fish to Jones Jr who only stepped out of the ring two years ago.
Tyson vs Jones Jr will be to launch 'Iron Mike's new venture 'Legends Only League' which "will support athletes in their individual sports, creating some of the most epic competitions, products and live events in the world".
The California State Athletic Commission, who will licence Tyson and Jones Jr, told Sky Sports that this will not be a regular boxing match.
"In this match, the referee will have the authority to stop the fight if it strays outside the boundaries of a competitive boxing exhibition," a statement from the commission read.
"Mr. Tyson and Mr. Jones Jr will have to submit all CSAC medical tests for fighters over 40 as well as CSAC's emergency regulations that have been put in place to slow the spread of COVID-19."
The commission's executive director Andy Foster told Yahoo: "This isn't a situation where they're going out there to try to take each other's heads off."
But boxing has no equivalent to a pre-season friendly and the history of exhibition bouts suggests pretty much anything could happen.
In 2006, just a year after retiring, Tyson stepped into the ring without headgear against Corey Sanders for a series of exhibitions. A viral clip shows Tyson landing a right hook and Sanders clearly going limp. Tyson held his rival upright and went easy on him thereafter.
But Floyd Mayweather? Not so much.
On New Year's Eve 2018 with his 50-0 record intact and as the winner of boxing's two most lucrative fights ever, the next step of the Mayweather journey was to visit Japan for an exhibition (whatever that meant) against a local kickboxer called Tenshin Nasukawa.
Nasukawa was 21 years younger, vastly less experienced, suited to a much smaller weight division and, of course, not actually a boxer.
Mayweather floored him three times and knocked him out in the first round.
"It was all about entertainment. We had fun," Mayweather said as his beaten rival burst into tears. "I'm still retired. I don't look forward to coming back to boxing. I did it just to entertain fans."
There is clear intrigue in Tyson and Jones Jr stepping into a ring and exhibiting their legendary skills, however they choose to do so. But if the punches really fly? Tyson may regret it.