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

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. 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

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.

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.

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 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.

With each corner eager to dominate, things could be more intriguin, buf should both men show each other too much respect, then fans could be in for a very dull 12 rounds indeed.

If it's a decent fight, then they will probably do it all again in September.