FLOYD MAYWEATHER stalks the camera, feints a little to his left.

He toys with the lens. Toys with it the way he's toyed with and tormented 47 of the finest fighters the world has sent his way over these past two decades of sheer, devastating domination. He moves in, so close that his face takes up the entirety of the documentary maker's screen and delivers the line like he's delivering a decider. "Money isn't everything," he says. "It's the only thing."

For the man who has long since eschewed conventional honourifics, demanding to be known not as Mr, Sir, or Rt Hon but instead 'Money', it's hardly the kind of declaration that would shatter the earth. It's his opinion. He's entitled to it. He won't be slow in letting you know as much. But for those of us who come from more traditional schools of thought, timing is still everything. For the Fight of the Century, timing isn't the only thing but it is everything.

Tonight in Las Vegas, a city of 1.9million people but not a single clock, timing will decide all. Sin City's casinos don't want you to know what hour of the day it is. They do everything in their power to tie the hands of time. Hey, why worry about minutes and seconds when there's another wheel to be spun, another hand to be dealt, another dice to be rolled?

But not even the wondrous watch-stoppers of Vegas will be able to hold back father time tonight at the MGM Grand's Garden Arena. The prizefight the planet has waited six years of forever for is here. Floyd Mayweather is here. Manny Pacquiao is here. The fight, no, The Fight, the one that needs only capital letters rather than individuals for identity, is here. Set your watches. If you live in another part of the world set your alarm clocks. Seconds are about to be out.

Fight of the Century sounds so grandiose that one almost forgets that this century is barely in its mid-teens. It sounds good though. It probably sounds better than Fight of the Generation. But the latter would fit better.

Between them Mayweather and Pacquiao have fought 111 fights in 39 combined years as professionals. The Filipino made his debut in early 1995, by which time Mike Tyson had already fought 40 times. A couple of months after Mayweather lit up the Atlanta Olympics in summer of 96, Tyson lost his heavyweight title to Evander Holyfield, the precursor to the earlobe infamy of the rematch the following year.

It was the end of a generation. The beginning of another. The intervening times have been all about Mayweather and Pacquiao, the MayPac generation if you like. Others have come and gone. The Klitschko brothers have been peerless pros but big fish in a drying-up pond who refused to countenance eating one another to survive. A Mexican murderers row of flyweights gave us some of the most crimson canvasses in memory but Barrera, Morales and Marquez were too fast, too loose to define the times.

Oscar De La Hoya, meantime, lost six of his last 14 fights to leave a golden career without the necessary shimmering finish. His final three trips to the ring featured two comprehensive defeats. The victors? Mayweather and Pacquiao. The latter's TKO sent De La Hoya into retirement and kicked off the first calls for tonight's fight to be made. By the time Pacquiao put paid to Ricky Hatton and Miguel Cotto, the calls had become a clamour.

That's a full six years ago. The fathers of the generation sure as hell took their time. Mayweather is 38 now, Pacquiao 36. Many say they've left it much too late. Yet this week, here in the capital city of boxing, others have argued otherwise. There's a feeling that the finest pound-for-pound men in a lifetime might just have let their meeting mature to its most palatable point.

"All great fights happen sooner or later. Right now, it's the perfect time for this fight," insists Freddie Roach, Pacquiao's trainer, confidant and best friend.

Given the wait, given the marathon rally of back and forth before the fight was finally, mercifully agreed, given the incredible hype of recent weeks, it has, at times, been hard to remember that at the end of all this there's the small matter of the fight itself. The best counter-puncher most of us have seen against the best attacking fighter we've ever laid eyes on. Defensive dancer meets frenzied swinger. The runner versus the rumbler. Mayweather fights like he's always a couple of steps ahead. Pacquiao fights like there's no such thing as steps.

If styles makes fights, it sounds like a beautiful, bewitching construction. But that ignores the unprecedented tactical preparation of both camps. Roach and Mayweather's tandem of father Floyd and uncle Roger aren't seeking a beautiful fight. They'll forgo something spell-binding for something solid.

"I'm more calculated. I'm the smarter fighter," said Mayweather midweek. "He would be a better fighter if he wasn't so reckless - it's a gift and a curse, he's won a lot of fights by being reckless but you can be reckless and get knocked out. And getting knocked out in a harsh way can affect you in the long run."

It's a fair observation. But Roach, the smarter trainer, has felt like a man with a plan. As cornerman for De La Hoya in that 2007 defeat to Mayweather he came close to masterminding victory but his fighter tired and lost discipline.

As the younger man by two years fatigue shouldn't be an issue for Pacquiao. As a man who has tasted defeat five times already, he has placed an infinitely greater value on discipline as he rebuilt his career. Arguably he could now be more disciplined than Mayweather, a man whom knows no other way out of the ring than as victor.

"Manny's speed will overwhelm Floyd, that's what we're counting on," said Roach. "It will be very difficult for Floyd to win this fight just by running and at some point he will have."

Having taken so long to get here, it's unlikely that things will finish before schedule. A knockout has to be placed into the most unlikely of brackets. Mayweather hasn't ended a contest early in four years, going the distance five times since then. Pacquiao, meantime, hasn't KO'd an opponent since 2009 a full nine fights ago.

Going the distance would mean that managing the moments will be crucial. Registering a first or indeed only knockdown would be a sickening psychological blow. Should Pacquiao be able to burst out of the gates and take, say, four of the first six rounds, this writer feels that Mayweather would find that it's a very long way back. A lot longer than it used to be.

That's the thing about time. Even in Las Vegas, it catches up with you. It was bound to catch up with the MayPac generation. Money may well be the only thing for its namesake. But if Pacquiao and Roach can clock in their perfect performance then a brutal realisation may await Mayweather. A realisation that timing is still everything.