THE theme of Floyd Mayweather-Conor McGregor is lots and lots of noise. Shout loud enough and people listen. It doesn’t matter that what you’re yelling is a load of nonsense. Be persistent. Just keep yelling the same thing over and over again and people not only listen, they believe. Ahead of his invasion into boxing and a fight with Mayweather, McGregor has been ranting and raving for what seems like an eternity. And out here in an insanely hot Las Vegas, a lot of people are taking the words that rage from beneath his beard as the whole truth and nothing but.

If you hadn’t heard, McGregor – the MMA superstar-turned-boxing debutant – is going to beat Mayweather, the greatest boxer of his generation. Such an outcome is unthinkable among the majority of educated observers given the Irishman’s minimal experience (his record of 0-0 looks ridiculous compared to his opponent’s 49-0). No matter, the supremely confident McGregor is declaring that he won’t just beat Mayweather, he’ll knock him out.

At today’s Grand Arrivals, McGregor – dressed in a typically dashing suit – joined his fans and made his victory call again. During their foul-mouthed world tour in July, McGregor predicted Mayweather would be beaten inside four rounds. Last week he halved it to two and today he bellowed his rival would fall in one.

“I’m calm and cold, just like I am before all my fights,” McGregor said today. “I believe he’ll be unconscious inside one round.”

That’s right, McGregor is going to knock out Floyd Mayweather in the opening round. Inside three minutes, within 180 seconds, which is less time than it takes to make a Pot Noodle. McGregor will find his range, set a trap and make Mayweather wither quicker than dried pasta in boiling hot water.

In his hometown, Mayweather is again the villain. Today some fans booed as he greeted them, while McGregor – chased by camera crews – did a lap of honour among his before confronting both his opponent’s team and recent enemy, Paul Malignaggi. His sparring partner is obviously still enraged with being made to look like he came out second best during their now famous sessions, and  he advised the Irishman to “bring his balls into battle.” The whole thing was predictable, and largely unremarkable but the grudge that is growing between Mayweather and McGregor appears to be real.

Throughout the build-up, Mayweather – as ever the master salesman – has made admissions that he’s not the fighter he once was, he’s fuelled propaganda that he hasn’t trained as hard as he used to and has talked up McGregor’s chances. As the contest draws closer, though, the American has found it harder to disguise his real feelings towards his opponent and today indicated he will triumph via knockout. And for the sake of the sport that made him, one hopes (and presumes, it must be said) that turns out to be the case.

Everything about this matchup has been bold, not least the promoters’ promise that this is the most highly-anticipated bout in boxing history. Whatever you think of the contest, whether it be a must-see event or diabolical mismatch, it’s hard to argue that it’s captured the imagination of the sporting mainstream far more than your standard boxing fare. However, the ticket sales indicate that the interest is not quite yet off the hook as, with a little over three days to go before the opening bell, there are still plenty of available.

And therein lies some comfort for the hardcore boxing fans who have taken a severe dislike to May-Mac. Behind the two fighters today, on the big screens outside the T-Mobile Arena, images advertising Gennady Golovkin’s September 16 showdown with Canelo Alvarez were joined by two telling words: Sold Out.