12 Days: Mayweather-Pacquiao

Will Floyd Mayweather Jr. budge from his demands to make a megafight with Manny Pacquiao? Johnny Nunez/BET/Getty Images

In the spirit of the holidays, ESPN is celebrating the season with our own "12 Days" wish list of the fights we want to see most, regardless of promotional or other entanglements. Keep checking back in the coming days to see new fights revealed, discuss our choices or even suggest some of your own in the comments section or via Twitter using #ESPN12Days.

When Muhammad Ali and Joe Frazier were the best heavyweights in the world, both undefeated and both with a claim to the title, they eventually fought. Because the public demanded it, because each could make his biggest payday and because they dared to be great.

It became one of the most storied rivalries in sports history and produced boxing's most famous trilogy.

Showdowns between all-time greats do happen, but it's rare when they take place with fighters at the peak of their powers. It happened when Sugar Ray Leonard and Thomas Hearns met to unify the welterweight title more than 30 years ago, a fight still talked about today.

In more recent years, the one fight that transcended boxing, one that even casual sports fans were interested in, was a showdown between Manny Pacquiao and Floyd Mayweather Jr. It has yet to happen, and its prospects look bleak.

Filipino icon Pacquiao is the humble spirit and whirlwind power puncher who has won world titles in a record eight weight divisions, has been named fighter of the year three times and was the 2000's fighter of the decade. Mayweather is the brash, technical wizard who is undefeated and has won world titles in five weight divisions. He also has a fighter of the year award to his credit.

For a few years, Pacquiao and Mayweather were regarded as the two best fighters in the world, pound for pound. However they ranked, they were always 1-2 (or 1A and 1B, for that matter) -- and nobody else was seriously in the conversation. And, oh yeah, they were both welterweights and beating many of the same opponents, including big names such as Oscar De La Hoya, Ricky Hatton, Juan Manuel Marquez, Shane Mosley and Miguel Cotto.

As all fight fans know by now, unless you've been on Mars or under a rock, the sides have tried to negotiate the fight multiple times, including, most notably, the first try in late 2009 for an early 2010 fight. In my estimation, it would have generated more than 3 million pay-per-view buys and left the record in the dust. I think the fight would have easily shattered every single boxing revenue record known to mankind.

It was a fight the world was begging to see. It was the ultimate showdown between boxing's best, two men with opposite personalities and contrasting styles.

The camps had worked out every single issue -- from purse split (50-50) to a date and location -- with one exception. Mayweather demanded that both fighters undergo random drug testing -- blood and urine -- leading up to the fight. At the time, Pacquiao objected to blood testing so close to the bout, and the deal cratered.

A second negotiation, one the Mayweather camp still has never admitted even took place (even though Pacquiao's side and HBO, which was involved, said it did), went nowhere. By this time, Pacquiao was OK with random blood testing (which he underwent for his Nov. 23 fight with Brandon Rios), but Mayweather had other ideas and wanted a lot more than half the money. When he and Pacquiao spoke directly on the telephone about a possible fight, Mayweather offered only a flat fee to Pacquiao rather than a rightful percentage of a promotion that might be worth in excess of $200 million.

The rancorous issues between Pacquiao promoter Top Rank and Mayweather adviser Al Haymon and Golden Boy, Mayweather's de facto promoter, were also huge roadblocks to making the fight.

While Mayweather has remained on top and is now the clear pound-for-pound king, Pacquiao suffered a pair of losses -- a bogus split decision to Timothy Bradley Jr. and a rough knockout to Marquez in their fourth showdown. Those results cooled excitement for the fight. But after Pacquiao rebounded with such a dominant win against Rios, the fight is on people's minds again.

And although it will never, ever be what it should have been -- the two best facing off at their best in 2010 -- it's still the biggest fight boxing has to offer, by far.

But that hasn't made a difference for the past several years and, sadly, doesn't appear to mean anything now, either, as both fighters remain as far apart as ever.

Pacquiao is due to fight April 12 and Mayweather on May 3. Neither has formally announced his opponent, but one thing you can take to the bank: They won't be fighting each other. And for all of boxing, that is a shame.