OPINION: Ronda Rousey is the single-most unstoppable fighter in mixed martial arts history

Ronda Rousey is the one fighter who I can truly see finishing her mixed martial arts career undefeated.

The women's bantamweight champion took on her supposed biggest test at Saturday night's UFC 184 in Cat Zingano. And "Rowdy" needed just 14 seconds to pass that test with flying colours. That begs the question, "who can beat Ronda Rousey?" and my answer is a resounding "nobody." There are a few options open for the UFC to pit against their only undefeated champion... Bethe Correia, Jessica Eye, Holly Holm and Cyborg. Jessica Eye (11-2, 1NC) is nowhere near the level required to deal with the grappling credentials of Ronda. The Ohio fighter burst into the consciousness of the more casual fans when a punch caused the ear of last opponent Leslie Smith to essentially explode. Having said that, Eye has a submission loss on her record to our very own women's warrior Aisling Daly. https://www.youtube.com/watch?v=RLEU3cEPI_U Ais "The Bash" submitted the American via rear-naked choke back in 2011 in a flyweight encounter. That doesn't fill one with hope of Eye's ability to deal with the superior ground game of a bigger, stronger, more decorated grappler in Ronda Rousey. Bethe Correia (9-0) has looked like an animal to be fair. She's an aggressive fighter who also boasts an undefeated record but the calibre of fighters she's faced pale in comparison to that of the champion. That's not to say a Rousey - Correia title fight isn't compelling for fight fans. It probably makes the most sense in terms of match-ups the UFC can make for "Rowdy" insofar as Correia has already beat two of Rousey's training partners and friends in Shayna Baszler and Jessamyn Duke. https://www.youtube.com/watch?v=TJ3J8MmeKPI The intrigue of the fight does not necessarily mean that the Brazilian stands a chance against the American. Of course everyone with power stands a puncher's chance of winning any fight but the ease with which Rousey has dispatched nasty strikers like Liz Carmouche, Miesha Tate and Cat Zingano means a fight with Correia will likely go a similar way, namely a first round submission. It seemed like the UFC were preparing Holly Holm (8-0) for a title shot when she made her promotional debut in the co-main event on Saturday and there was almost a sense of her opponent, Raquel Pennington, being thrown to the wolves against the former pro boxer. But the fight was a much tighter affair than the UFC would have anticipated/hoped for with Holm being awarded a split decision rather than finishing Pennington with devastating strikes as many expected. That all but rules out Holm facing Rousey next and with Holm being 33 years old, the longer that fight takes to come to fruition the worse Holm's chances look. With Rousey's seldom-used striking improving every time we see her, you'd bank on her being able to cope with the boxing of Holm if the UFC newcomer displays the same stand-up that she did last weekend. Then comes the person who would undoubtedly offer Rousey the biggest test, Cris "Cyborg" Justino (13-1, 1NC). https://www.youtube.com/watch?v=AcY90ezsrSU The main stumbling block for a Rousey v Cyborg fight is the fact that the Brazilian cuts to make it to 145lbs, Rousey fights at 135lbs. Cyborg is planning on fighting at bantamweight at an Invicta event this summer so it will be interesting to see if she can make the 135lb weight limit for a title fight. If she can drop the extra pounds, Cyborg could cause Rousey problems in as much as she's an absolute beast who has only been the distance twice in a ten-year fight career. It would certainly be the only fight where the odds wouldn't be ridiculously in Rousey's favour, although she would still be favourite. While we're currently talking exclusively in speculation and hypotheticals, you'd have to give Rousey the nod based solely on the fact that she has yet to even be tested while Cyborg has a loss on her record, a submission loss at that. Another issue is Cyborgs history of PED use. Her victory over Hiroko Yamanaka was overturned to a No Contest after she was popped for an anabolic steroid so you'd have to wonder how natural her abilities are when compared to Rousey who tested clean ahead of her fight with Zingano and has never shown signs of PED use. So now that we've established that Rousey will likely see off all comers put in her way, we ought to look at where she ranks on the list of all time greats in the unstoppable standings. There are also four main contenders who most fight fans would have considered "unstoppable" in their heyday are Anderson Silva, Fedor Emelianenko, Georges St-Pierre and Jon Jones. We can rattle those guys of fairy easily when you compare them to Rousey. Anderson Silva was once in the same category as Ronda Rousey and, despite having a few losses to his name already, nobody knew who could overcome the Brazilian between 2006 and 2013. But then came the mother of all answers when he was knocked out cold by Chris Weidman before snapping his leg horrifically in the rematch. After rebounding with a decision win over Nick Diaz, he tested positive for performance enhancing drugs, which means that victory will more than likely be overturned to a No Contest. That means "The Spider" hasn't won any of his last three bouts which sends him crashing out of the "unstoppable" group. Fedor had a similar end to his career. Emelianenko, undoutbtedly the greatest heavyweight of all time, went eight years without tasting defeat and many considered him an unstoppable force during his PRIDE days. But, just like Weidman shocked the world against Silva, Emelianenko got caught in the triangle of Fabricio Werdum which set up a run of three straight defeats for "The Last Emperor." That also takes the "unstoppable" moniker away from the Russian. Georges St-Pierre was close to unstoppable status throughout his career. Both times he lost were sort of flukey. There was a second remaining in the round when he lost to Matt Hughes and his loss to Matt Serra has to be put down to that "puncher's chance" kind of finish. What was more damaging to GSP's reputation as an irresistible force in the UFC's welterweight division was his victory over Johny Hendricks. "Rush" was beaten from pillar to post in that fight, which would prove to be his last before he decided to vacate the title and Hendricks' display that evening, in defeat, showed the blueprint of how the Canadian could be defeated. The only fighter remaining, and the closest one to Rousey in my opinion, is Jon Jones. The light heavweight champion is 21-1 in his mixed martial arts career but he should really be undefeated with his only loss coming by way of disqualification after landing an irrationally illegal elbow on Matt Hamill in 2009. https://www.youtube.com/watch?v=6h7sa6RM8tM The only thing separating Jones and Rousey is the fact that "Bones" has come through some serious tests in recent years, the most significant coming against Alexander Gustafsson. While we would call Jones somewhat unstoppable, his war with the Swedish 205lber showed that he is not able to dominate each and every fighter. Rousey, meanwhile, has never really looked in trouble in her UFC career and we truly don't see anyone testing the UFC bantamweight champion before she retires. She also seems clever enough to get out before it's too late. It's too often that fighters wait until they get knocked out badly before hanging up their gloves. Rousey seems too intelligent to let that happen and, if I'm honest, it wouldn't surprise me if she calls it a day in the next two years to pursue a career in acting or as a professional wrestler. PREDICTION: Rousey will fight Correia next, then Holm, then Cyborg before finishing her career at an impressive 14-0.