Five Rounds: Who would win a mythical Mayweather-McGregor fight?

Each week, ESPN.com writer and MMA Live Extra analyst Brett Okamoto provides his take on the hottest topics in the world of mixed martial arts.

This week, Okamoto squares off with ESPN.com senior boxing writer Dan Rafael to discuss the wild premise of a fight between retired boxing superstar Floyd Mayweather and UFC featherweight champion Conor McGregor.

The worlds of combat sports collide in this special edition of "Five Rounds."

1. Could a fight (under any rule set) between Mayweather and McGregor actually happen?

Okamoto: No! A fight between these two could only "actually happen" in the same way getting struck by lightning twice on the same day as you win the lottery could "actually happen." I'm going to get on a soapbox for one second (and one second only, I promise). It's saddening to me that all it takes for millions of people to start talking about this fight is Mayweather uttering the word "possible" and McGregor tweeting a photoshopped picture of the two looking at each other. The UFC isn't going to let McGregor box, and Mayweather is definitely not stepping into an MMA fight. If this one ever happens, it's in a professional wrestling ring where the outcome is written in a script. These two seem to be having fun with it though, and why not? If that's all they have to do to make national headlines, they'd be fools not to. If they're willing to have fun with it, then I guess Rafael and I can have fun with it. But know that to even address this nonsense pains me a little.

Rafael: No! How could it happen when they are both (well, at least one) retired? Seriously, this is such a joke but, hey, the bosses said my man Brett and I should discuss it because there are so many people interested in this nonsense that we might as well get the clicks, too. I like talking about real fights, not fantasy silliness that has less chance of happening than Cain-Abel II or even Muhammad Ali-Joe Frazier IV. But fine, I'll play along, briefly. Let's just say for a moment that is to be taken seriously (which it is not!). In which discipline do they fight -- boxing or MMA? That's a deal-breaker, right? I don't know McGregor, but I do know Mayweather and there is no way he gets in the cage. None. They could spend a week locked in a room and not come to an agreement on that pretty important element. Besides, does anyone really think UFC is going to let McGregor out of his contract to do this? I'll let the rest of the world do mental cartwheels over this nonsense while I stick to real fights. Are we done yet?

2. OK, but if they were to fight -- who wins and how?

Okamoto: Welp, guys, it's pretty simple. Boxing match: Floyd knocks Conor out, with ease. He toys with him, clowns him, smiles at him -- I guess he did that to many of his opponents anyway, but it would be more so against McGregor. I would give McGregor very little chance to make it 12 rounds -- almost none. This strikes me as common sense; we're talking about the greatest boxer of his era against a nonboxer. Of course he would knock him out in less than 12 rounds. If it's any other kind of fight, Mayweather is getting hurt, bad. Again, this is common sense! McGregor's kickboxing would separate Mayweather from consciousness in a matter of minutes, possibly seconds. I mean, honestly, when people talk about this potential matchup, what do they even talk about? What is there to have differing opinions on? Mayweather wins a boxing match. McGregor wins anything else.

Rafael: Gotta agree with Brett on this one. Take this to the bank: In an MMA fight, Mayweather would get obliterated. He's a great boxer, not a guy who works with his legs or grapples, so he'd get taken down or get kicked in the face and that's all she wrote. He'd be 49-0 in boxing but quickly 0-1 in MMA and would be wondering what the heck had just happened. If they go the boxing route -- the only way Mayweather would even remotely think about engaging in this kind of farce -- he would embarrass McGregor. He would toy with him, humiliate him, make him look worse than a novice amateur and knock him out even though he's not a puncher. But he'd be fighting a guy with zero boxing skills. As Mayweather probably would say, "Easy work." It would be a no-hitter. Not the baseball kind but the kind in which Mayweather might go the entire fight without getting hit anything of significance before he scored the KO. Are we done yet?

3. What other boxing vs. MMA matches could be made to fill out this kind of fantasy card?

Okamoto: A boxing and MMA extravaganza! The rules: Four rounds of boxing with one final round of MMA rules (translation: boxers better go for that knockout in the first four). The undercard: Tyson Fury-Fabricio Werdum, Manny Pacquiao-Donald Cerrone, Gennady Golovkin-Robbie Lawler, Canelo Alvarez-Nate Diaz, Andre Ward-Nick Diaz and Wladimir Klitschko-Jon Jones. Plus a special attraction in which promoters Bob Arum and Dana White get 45 seconds each to sell us "a mysterious paper bag, contents unknown!" Whoever draws the highest bid gets the win.

Rafael: I do not fantasize about these matters. I do fantasize about Canelo-GGG, Sergey Kovalev-Andre Ward and Roman "Chocolatito" Gonzalez-Naoya Inoue, not to mention mythical matches like Sugar Ray Robinson-Sugar Ray Leonard, Roberto Duran-Manny Pacquiao and Marvin Hagler-Bernard Hopkins. But if you stuck a gun to my head, I wouldn't know enough MMA fighters to (A) have an opinion whatsoever or (B) even have any idea which weight class the guys I do know are in. Are we done yet?

4. Would boxing or MMA fans watch, and would it be good or bad for the health of either sport if it actually did happen?

Okamoto: Boxing fans, MMA fans, casual sports fans, nonsports fans -- they'd all watch. Would that have an impact on either sport, good or bad? In some ways it would marginalize both, would it not? Sort of like a joint statement of, "We're desperate for your attention." At the same time, it would generate an avalanche of global media attention, which is good for the two athletes involved, which in turn is good for the respective sports, right? All in all, I'd say the long-term effects would actually be somewhat negligible. Boxing's problems in terms of the best fights (not) being made and bickering promoters go beyond any positive or negative effect that one freak show fight involving Mayweather would have. And as far as MMA and McGregor, who is in his prime, are concerned, his star power (and the positive effect it has on MMA) would still be contingent on him winning in MMA at a high level. So, there'd be short-term effects but not as much in the long term.

Rafael: If a card with well-known boxers and MMA fighters actually was made (and it won't be!), sure, I'd watch, as would many others. I'd watch like I check out car wrecks on the side of the road, slowing down and just having to take a look. It would garner a lot of breathless media coverage but, again, in which discipline would the bouts be fought? Basically, any boxer of merit would hammer out an MMA fighter with relative ease the same way an MMA fighter would likely dominate boxers in any fighting discipline other than boxing, unless the boxer got lucky with a flush punch. I don't think it would help or hurt either sport or prove a damn thing one way or the other. Are we done yet?

5. Who would commentate? Who would referee? Who would each fighter walk out with? And what would it cost to watch it from home?

Okamoto: There are so many options. Boxing commentating team? MMA? Go outside the box and bring Joe Buck's playoff voice to the table? Chris Berman? I feel like a late-night television show host might even be appropriate. Jimmy Fallon could probably make it work. Nope, wait, I got it: This calls for Cotton McKnight and Pepper Brooks. I would say Mayweather walks out with Justin Bieber as he has in the past, but we know Biebs is a McGregor fan! So, I guess JB walks out with one, hustles back and walks out with the other. It's only fair. And for the viewers at home, this one would cost no less than $200 per buy. Plus a small piece of our collective souls.

Rafael: Gotta get my man Mauro Ranallo in there somewhere because he has a lot of experience calling boxing and MMA, not to mention WWE -- and this is, after all, a circus worthy of a WWE announcer. And how about we get Jim Lampley in there to work with Joe Rogan? By the end of the card they'd probably be beating the crap out of each other just to add to the chaos as they argue the merits of each sport. Mayweather wouldn't need to walk out with anyone. He knows he's so great he could just levitate toward the ring/cage. McGregor should walk out with Dana White because I guess they're BFFs again. As for the cost of this once-in-a-lifetime opportunity? I'll agree with my man Brett: $200 -- but $220 in HD -- to go with a large chunk of our self-respect. Are we done yet?