Wow, what a debate. Personally, I wouldn't even try to make a call on a fight like this one. Face it, when watching NHB fights, how many times does the predicted outcome actually match the actual outcome? Sometimes it does, but many times we see things happen that we would never expect. Two groundfighters may stand up and strike throughout the whole match, or a "striker" may tap out a "grappler".
Point is, no one knows what would happen in this matchup, despite what we may see on paper. We can assume that if it were to happen, it would be planned months in advance. This would give Tyson a small opportunity to train in groundfighting, and Rickson to train with some talented strikers (if he even needed it). Granted, despite any training he does, Tyson wouldn't be able to match Rickson's profiency on the ground. But he would certainly know that fact. At the same time, Rickson would be keenly aware of the dangers of Tyson's boxing style, also.
We are all aware that boxing isn't the same as NHB. On paper, a NHB fighter would defeat a boxer. Boxing simply is too restrictive a sport to match up to the many options that a NHB fighter has in his arsenal. Remember that boxing in itself is a science. A boxer uses footwork, timing, speed, experience, endurance, power, and strategy to achieve one desired goal: to hit his opponent above the waist more times than his opponent hits him, thus winning on points. Of course, a knockout gives an automatic win. During the course of a fight, a fighter will study his opponent, watching for weaknesses and opportunities to land punches and score points. His strategy may take many rounds to play out, and he may have to change it if it isn't as effective as he and his camp had hoped. His footwork gets him in close enough to land punches, and gets him out before he gets hit. He can bob, weave, and block in an attempt to not get hit. His speed lands his punches before his opponent can react, and his power wears his opponent down over time. He learns how to throw punches efficiently, without telegraphing them. It is indeed a sweet science.
Tyson will go down in the books as one of the greatest at this science. But let's see it for what it is: trying to hit your opponent in strategic areas of his body above his waist for 3 minutes, rest 1 minute, then do it again, while a referee breaks you both up every time you clinch. Not exactly what would happen in a no-holds-barred environment.
I've seen many a Tyson fight, and I know that many out there can agree that he's been in many clinches in his fights, even in a single round. Problem is, in a NHB fight, there isn't going to be a referee there to separate him and his opponent. In a fight between Tyson and Rickson, a clinch would certainly be in Rickson's favor. Of course, it can be argued that in order for Rickson to clinch Tyson, he has to approach him first. You know what that means: if Rickson got close enough for Tyson to throw a punch-KNOCKOUT! Right?
Well, first of all, Rickson isn't going to deliberately stay in Tyson's punching zone for any amount of time, much less stay there long enough to get hit. He would try his best to pass through Tyson's punching zone as fast as he could in order to get close enough to clinch. Once that happened, it would most likely fall in Rickson's favor. If he can get that far. But Rickson has experience doing this very type of strategy against strikers, so he may be able to pull it off.
But Tyson isn't just any striker. He's the former world heavyweight boxing champ, right? His footwork should be able to keep him away from a clinch if Rickson shoots in, maybe. All he needs to do is land one haymaker, and its lights out for Rickson. Ahh, but remember, who says that every punch Tyson throws is a knockout punch? If that were the case, Tyson would be undefeated up to this day. Realistically, although Tyson has had some spectacular KO's, even he has had to pummel many of his opponents with punch after punch before the KO occurred. True, Rickson isn't a professional boxer, but I don't think Tyson landing one or two punches will necessarily knock Rickson out. I come to this conclusion because I don't feel that Rickson would put himself in the position that it would take for Tyson to land that type of blow, which would be standing straight up in front of Tyson. If they were that close, you could be sure that Rickson would be attempting (key word: "attempting") to shoot in low, putting his head at about the same height as Tyson's lower waist. With a target that low, moving no less, I don't feel that Tyson's punches would be as effective as they are when he's KOing his opponents that are standing straight up right in front of him. Can Tyson's footwork move him fast enough to dodge a shoot-in from someone as proficient at it as Rickson? If Rickson clinches or shoots in and takes Tyson to the ground, I feel that Tyson's chances of victory would grow pretty slim. Some would say that even if the clinch occurs, Tyson still could knock him out. I don't see how. How many times have you watched a boxing match and seen a fighter get knocked out while clinching his opponent? Never. A boxer simply cannot apply the body torque needed to do that. He can punch the kidneys, and the side of the head of his opponent, but there's not a whole lot behind the punches. But Tyson is a monster, with unbelievable power! Well, I wouldn't say that he has any more power than many of the NHB fighters out there. I'm sure that Tyson would be very well conditioned for the fight, but boxers generally stay away from weightlifting, instead training their muscles to be fast and quick. In other words, Tyson's power may be something that Rickson is familiar in dealing with. In which case, Tyson would be in trouble if he were to be taken to the ground.
We know that there isn't very much in the way of stand-up striking in the way of Gracie ju-jitsu. We can assume that Rickson won't even attempt to do any stand-up striking, since that would be certain defeat. But that is the definition of Gracie jujitsu: why stand up and strike, hoping to be superior to your opponent when you can take him to the ground where you KNOW that you are superior to him? To think that Tyson could go against Rickson move for move on the ground would be preposterous, despite Tyson's strength. Tyson may have been one of the greatest boxers in the world, but he isn't superman. His joints can be overextended just like anyone else's. He can be choked out like anyone else. There are some NHB fighters out there that would make Tyson look tiny if he stood next to them, and they succumb to joint locks and chokes, so he certainly would, too.
But I can't help but think of something: Royce vs. Kimo. Royce was 178 lbs. I believe, and Kimo was 235. Although the strategies and techniques of Gracie jujitsu gave Royce the victory that night, Kimo, with his tremendous strength, gave Royce a helluva beating.
Now we consider Tyson vs. Rickson. Tyson, although not tall, is a big monster of a man, with Rickson not so big. If Tyson's strength was to give Rickson as much trouble as Kimo gave Royce, Rickson may find himself waking up from a KO. We know that Tyson has more striking experience, speed, and power than Kimo. Therefore he would use his opportunities to strike more effeciently, and with more effectiveness.
Couple that with the fact that in this day and age, fighters are now more proficient in dealing with fighters who are strictly ground practitioners. We see many times nowadays a fighter who doesn't want to go to the ground being more successful in preventing himself from being taken to the ground by a groundfighter. Techniques and practice in defending oneself from being taken to the ground is now being incorporated into many fighters arsenals. Surely, if Tyson were to fight Rickson, he would look into this, and invest time into learning as much of it as he could.
And it would be silly to think that Tyson would limit himself to just his punching skills. He would most likely study up on other disciplines, in an attempt to understand Rickson's skills. But when it comes down to it, all Tyson would really have is his striking. If Tyson could power out of Rickson's moves and techniques enough to land a punch hard enough to hurt him, even for a moment, Tyson could very well go on to end the fight from there. Quickly, too.
I think everyone agrees on one thing: one of them would demolish the other. No one is saying, "ooh, that would be a close fight!" For me, as I said earlier, too many times what we could see on paper and what actually happened in fights was two different things, although many times it went exactly as predicted. Problem here is, how do you predict a fight like this? You can't. Probably, the only way (without them actually fighting) would be to meet someone who knows the boxing world as well as the NHB world, and who has personally worked with both Tyson and Rickson, and get thier opinion. Even then, that's exactly what it would be-an opinion.
The way I see it is that Tyson would, by far, be better conditioned and physically stronger than Rickson. Tyson has devastating, world-class punching skills. Rickson's punching skills would be non-existant in comparison; but Rickson's very discipline is to render punching skills useless, anyway. Tyson's groundfighting skills would be inadequite, despite any last minute preparations. Tyson may have enough power to render many of Rickson's techniques useless, despite his profiency at applying them. Maybe not.
Tyson would be stepping out of his element, right into Rickson's game. Rickson, like the rest of his family, has been practicing NHB his whole life, and that would be his advantage over Tyson. Would it be enough?
For my money, I would have to go with Rickson.