"The Baddest Man on the Planet."

The first time I heard that term, it was being used to describe Mike Tyson. I'm sure someone somewhere described Muhammad Ali that way back in his day, and before him Rocky Marciano and Jack Dempsey and Jack Johnson. The idea was that prizefighters are the world's alpha males, and the heavyweight champion the alpha among alphas.

But just as boxing itself has seen an audacious challenger get up in its face, so has the heavyweight champion of the sweet science. Nowadays you're more likely to hear a mixed martial arts heavyweight being cast as the Baddest Man on the Planet. What happened to James Toney within the first 18 seconds of his fight with Randy Couture last year is what would likely happen to any boxer who stepped in with an MMA fighter of comparable size and skill. (Unless he's fighting Tim Sylvia.) You can have the most lethal left hook in the business, but it don't mean a thing if you ain't got that takedown defense.

For years the planet's presumed baddest MMA man -- though Dana White hates to hear this -- was Fedor Emelianenko. Then, when Brock Lesnar reigned supreme in the UFC, he liked to affix the label to himself, although he rephrased it as "the toughest SOB around." But then Cain Velasquez came along and proved to be an even tougher SOB. And more than a year later, we now have another new Baddest Man on the Planet.

Junior dos Santos needed just 64 seconds to show that to the world -- or at least to the 8.8 million who watched the UFC's network television debut on Fox two weeks ago. By knocking out Velasquez, the 27-year-old Brazilian earned the heavyweight belt, the "Baddest Man" moniker (unless one of the Klitschko brothers dares to step forward) and -- most prestigious of all, no doubt -- the No. 1 spot in the SI.com heavyweight rankings.

1. Junior dos Santos (14-1)

2. Cain Velasquez (9-1)

3. Alistair Overeem (35-11, 1 NC)

So, yes, dos Santos and Velasquez have flip-flopped at Nos. 1 and 2. Now that that's settled, my focus is on No. 3, a spot occupied for many months by Overeem. With his big-man summit with Lesnar just a few weeks away, I have to admit that I'm beginning to waver. Will Alistair be capable of handling Brock? As a striker, he's superior to Lesnar's last two opponents, Shane Carwin and Velasquez, both of whom exposed the big guy's fisticuffs deficiencies. But both of those guys also are decorated wrestlers, which allowed them to keep the fight where they wanted it. Overeem is a big, strong guy, and he's been training at Xtreme Couture, which has to help his grappling game. But can Alistair learn enough to enable him to keep Brock from taking the bout down to his office?

1. Jon Jones (14-1)

2. Dan Henderson (29-8)

3. Rashad Evans (16-1-1)

You snooze, you lose. That's the rationale for dropping Evans one spot, leapfrogged by Henderson. Dan deserved something for his early ferociousness and late perseverance in his win over "Shogun" Rua two weeks ago, and all Rashad has to show for his last 18 months is a victory over a rejuvenated (but not that rejuvenated) Tito Ortiz. It's been reported that Evans will face Phil Davis in next month's second Fox show, so Rashad has a chance to build some momentum again.

1. Anderson Silva (31-4)

2. Chael Sonnen (26-11-1)

3. Vitor Belfort (20-9)

Nothing changes from last month. Nothing visible, anyway. If it were possible for you to see beyond the 1-2-3 of the division, you'd notice that there's someone closing in on Belfort, so much so that he's as much a No. 3a as he is a No. 4. And rising -- or at least with an opportunity to do so. I'm talking about Mark Muñoz, who beat up a pretty tough guy, Chris Leben, a few weeks ago. He's 12-2, winner of four straight, and next on his dance card is a meeting with Sonnen as part of the second UFC on Fox telecast next month. That's a bold step up for "The Filipino Wrecking Machine," although he wrestled Chael in college and claims to have beaten him "pretty handily." But that was wrestling, not MMA.

1. Georges St-Pierre (22-2)

2. Jon Fitch (23-3-1, 1 NC)

3. Nick Diaz (26-7, 1 NC)

Everything is holding steady here, too. Yes, even Fitch at No. 2. The UFC can pretend he's invisible, but here at SI.com he's seen more as invincible (unless he's in the cage with someone with the initials G.S.P.). Unfortunately for Jon, we don't make the matchups. The UFC has given Diaz the next shot at St-Pierre, and after that it could be Carlos Condit and then maybe Jake Ellenberger. Even Jon's training partner, Josh Koscheck, might get another chance at the belt before the efficient, not at all flashy Fitch.

1. Frankie Edgar (14-1-1)

2. Gray Maynard (10-1-1, 1 NC)

3. Gilbert Melendez (19-2)

In last month's rankings story I wrote that Ben Henderson was "one beatdown of Clay Guida ... from stepping in front of No. 3 Gilbert Melendez. Well, Henderson did beat Guida a couple of weeks ago, although even in a clear unanimous decision, I wouldn't exactly call it a beatdown. But that's not entirely why Melendez remains at No. 3. Gil has done nothing less than dominate everyone put in front of him, and it's not his fault that the Strikeforce lightweight division isn't the murderer's row standing in line for a shot at Edgar's UFC belt. Henderson gets his shot at Frankie next month in Japan, and if he wins that one, we'll definitely find a spot for him.

1. Jose Aldo (20-1)

2. Chad Mendes (11-0)

3. Hatsu Hioki (25-4-2)

Finally, Mendes gets what he has been patiently waiting for. The two-time All-America collegiate wrestler has done nothing but win during his MMA career -- with one exception. He was expected to face Aldo at UFC 133 over the summer, but with the champion still recovering from injury, the timing wasn't right and Mendes lost out. Kenny Florian ended up getting the title shot when Jose was ready in October. Now Mendes is getting his shot, although he'll have to take his 11-0 record to Aldo's home turf for the fight at next month's UFC 142 in Rio de Janeiro.

1. Dominick Cruz (19-1)

2. Urijah Faber (26-5)

3. Joseph Benavidez (15-2)

Didn't we just watch Cruz vs. Faber, like, last week? OK, it was five months ago that Urijah challenged for the UFC belt. He and "The Dominator" did win Fight of the Night at UFC 132, but Dominick won by a unanimous decision that wasn't so narrow. I haven't heard anyone calling out for a rematch, but that's what we're going to get after Faber, the former featherweight champion and the only man to beat Cruz (back in 2007, at featherweight), took out ex-bantam champ Brian Bowles a couple of Saturdays ago. Not only that, but we'll have to endure week after week of badmouthing buildup if, as is rumored, Urijah and Dominick end up coaching on The Ultimate Fighter. Why don't they just rename the reality show Groundhog Day?

1. Anderson Silva

2. George St-Pierre

3. Jon Jones

Silva is on the shelf for the time being, and St-Pierre is not in action until February. But we do get to see Jones defend his UFC light heavyweight belt and his spot in this P4P ranking this month, as he faces ex-champ Lyoto Machida at UFC 140 on Dec. 10 in Toronto. Obviously, I'm expecting "Bones" to win; otherwise, someone else -- maybe Machida -- would be ranked here. But while Jones will have an obscene advantage on the ground, and the length to make it difficult for the Brazilian karate man to reach him while they're standing, you never know.

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