|Mayweather v Pacquiao|
|Venue: MGM Grand, Las Vegas. Date: 2/3 May: 21:00 local time/05:00 Sunday BST|
|Coverage: Live text commentary on the BBC Sport website|
This weekend, American legend Floyd Mayweather will fight Philippine great Manny Pacquiao at the MGM Grand in Las Vegas. It's a bout so big that everybody is talking about it - so it's probably best you know your stuff.
Wow your hairdresser with tales of Mayweather's wealth and Pacquiao's upbringing; surprise your accountant with massive numbers; embarrass your ex's new partner with your superior knowledge of boxing tactics.
And be sure to keep this in your pocket at all times if you are attending a dinner party between now and Saturday - you don't want to look like a complete idiot.
Why all the hype?
In short, because Mayweather and Pacquiao are widely recognised as the two best boxers in the world - and it is a rare thing to have two all-time greats fighting in the same weight division at the same time.
Back in the 1980s, arguably the sport's last golden age in the United States, such match-ups were regular occurrences.
Fighters such as Sugar Ray Leonard, Thomas Hearns, Roberto Duran and Marvin Hagler were household names.
But boxing's disappearance from terrestrial television, the proliferation of governing bodies and boxing's internecine politics saw the sport recede from the public consciousness.
Boxing needed two genuine superstars to make it the biggest sport in the world again and it found them in Mayweather and Pacquiao.
What have they won?
Mayweather, 38, is unbeaten in 47 professional fights stretching back to 1996 and has won world titles in five different weight classes.
Pacquiao, 36, is a six-weight world champion (some say eight, although that includes a couple of minor belts) but has been beaten five times in 64 fights since turning pro in 1995.
Between them, they have victories over a host of fellow boxing greats, including Oscar de la Hoya, Marco Antonio Barrera, Erik Morales, Shane Mosley, Juan Manuel Marquez, Miguel Cotto and Britain's Ricky Hatton.
How big is it?
In financial terms, the biggest ever. By miles. Given the myriad revenue streams involved, it is impossible to say how much each fighter will walk away with once the fighting is done.
But it is estimated that once the accountants have done their work, Mayweather will pocket about £90m ($140-$150m) and Pacquiao £60m ($90m-$100m).
That the fight will generate so much money is largely down to the fact that American boxing fans will have to pay almost $100 (£65) to watch the action.
Mayweather-Pacquiao will shatter the records for pay-per-view buys (2.5m for Mayweather versus De la Hoya in 2007) and pay-per-view revenue ($152m for Mayweather versus Saul Alvarez in 2013).
The live gate at the 16,000-capacity MGM Grand Arena will be $74m, more than triple the previous record and more than this year's Super Bowl, which was watched by 70,000.
Tickets on the resale market are changing hands for six-figure sums, with most of that money finding its way back to the boxers.
Throw in foreign television money, sponsorship and merchandising and you're looking at double the gross domestic product of the Pacific nation of Kiribati.
What else is at stake?
In boxing terms, Mayweather's WBC and WBA welterweight titles and the WBO title owned by Pacquiao.
Also on the line is Mayweather's unbeaten record, while you could argue that Pacquiao doesn't have as much to lose.
Their fight will also go a long way to defining each other's careers: whoever wins will be able to claim they were the greatest fighter of their era, rightly or wrongly. As for the loser, there will be an awful lot of soul-searching to do.
Did they need the money?
In a word, no. Mayweather, who goes by the nickname Money, is already worth $295m (£192m) and earned $105m last year. Pacquiao, a relative pauper, is worth $110m (£71.2m).
Mayweather has banked more than $400m from boxing over his 19-year career and has been the highest-earning athlete in the world for the past three years. Pacquiao's feats in the ring across two decades have earned him $263m.
Mayweather's primary residence is a 22,000 square-foot, custom-built mansion in Las Vegas, although he also has a house in Miami.
He also owns two fleets of cars - a black fleet in Vegas, a white fleet in Miami - and his collection includes a couple of Bugattis worth more than $1m each.
He is also the proud owner of a 14-passenger private jet. Oh, and he only wears his trainers once.
PacMan still has a relatively modest abode in his home town of General Santos City, although he did recently splash $12.5m on a gaff in Beverley Hills.
Have they always been so lucky?
Both men had troubled childhoods. Mayweather was born in Grand Rapids, Michigan, into a family of boxers - father and trainer Floyd Sr was a welterweight contender and uncle Roger a world champion.
But his mother was a drug addict, while Floyd Sr was once shot in the leg by a fellow drug dealer while holding his son in his arms.
Pacquiao's family of seven lived in a cardboard shack in the poverty-stricken province of Sarangani in the Philippines.
He scrounged for food and on some days only drank water. He quit school at 10 and ran away at 15, after his father ate his dog.
For a while, Pacquiao slept rough on the mean streets of Manila.
But like many poor boys before and since, Pacquiao turned to boxing to feed his family, fighting for $2 a pop in the early days.
Is there more to the fight than cash?
Mayweather says no. And not surprisingly, there are those who find Mayweather's slavish devotion to Mammon somewhat distasteful.
As such, his fight against Pacquiao - who was raised a Christian but was only recently born again - is being billed by some as a battle between good and evil.
Some commentators have noted that this fight lacks greatness because it lacks a cultural dimension.
This is wide of the mark. Mayweather is rampant capitalism personified, as much a reflection of his era as Muhammad Ali in the 1960s.
As well as being a terrible braggart, Mayweather, a father of four, has also been a very bad boy. In 2011, he was sentenced to three months in prison after pleading guilty to assaulting his girlfriend at the time.
However, his stint behind bars was delayed on the grounds that the cancellation of his scheduled bout with Puerto Rico's Cotto would have cost the city of Las Vegas in the region of $100m.
Pacquiao is a more likeable individual. Witness his recent duet with movie star Will Ferrell on an American chat show, or a very amusing advert for a footwear company. Despite his many millions, Pacquiao just seems like a nice, humble bloke.
But Pacquiao has a dark side. He has admitted to adultery in the past - his wife, Jinkee, mother of his five children, was moved to tears when talking about it in a recent documentary - and in 2013 his assets were frozen in the Philippines after it was alleged he owed $50m in taxes. It should be noted, both men do a lot of work for charity.
Will it be a good fight?
The smart money is on the fight going the full 12 rounds - and on Mayweather being awarded the decision. And many think those 12 rounds will disappoint.
Mayweather is essentially a defensive boxer and has never been overly concerned about entertaining the fans. Pacquiao, on the other hand, is an all-action fighter - which could play right into Mayweather's hands.
If Pacquiao chooses a plan of all-out attack, then Mayweather could pick his rival off and win easily. If Pacquiao is more educated, which is more likely, then things could be more intriguing. If both men show each other too much respect, then we could be in for a very dull 12 rounds indeed.
According to almost every expert you talk to, Mayweather. Hatton, who lost to both men, calls Mayweather "a genius".
Hatton's fellow Brit Amir Khan, who wants to fight the winner, also believes Mayweather will be too clever.
However, Pacquiao does have some heavyweight backing, with former world champions George Foreman and Mike Tyson both picking him to win it.
If it's a decent fight, then they will probably do it all again in September.
Mayweather says he only has one more fight left in him - although with Rocky Marciano's record of 49 fights undefeated in his sights, he might fight on.
Whether Pacquiao chooses to fight on might depend on if he loses and the nature of that defeat.
He has a political career - he became a congressman in the Philippines in 2010 - and that might be his focus from Saturday onwards.