Yesterday Rizin announced that Floyd Mayweather would be fighting Tenshin on New Year’s Eve in Tokyo. The press conference had the desired effect, with the world’s media reporting the fight as if it was a done deal.

In reality, there is a huge amount of work to be done before this fight can happen and a very limited amount of time to get that work done. At present the only plausible way that the two men could end up sharing a ring on December 31st seems to be in a glorified sparring exhibition.

Here are three major obstacles which could potentially prevent Rizin from putting together this fight:


Tenshin can compete in kickboxing, Muay Thai and MMA and would be very comfortable in Karate, Jiu Jitsu, Sanda and numerous other combat sports

Mayweather is a boxer. He has only ever competed in boxing and has no experience or expertise in any other combat sport. At the age of 41 it’s highly unlikely he is about to start learning a completely new style, let alone accept a fight against a young star in an unfamiliar sport on very short notice.

Which means the only rules they could conceivably fight under are boxing rules but that will be very difficult to do because of the next two obstacles…


Mayweather’s last fight was at 154lbs; Tenshin’s was at 127.9lbs That means they are effectively separated by over 25lbs, the equivalent of five different weight classes.

We have weight classes for a reason. Fighters need to be of a similar size to make a contest fair and the current difference in stature between the two men means that they will be unable to fight in any sort of meaningful way.

A boxing match certainly wouldn’t get sanctioned although that didn’t stop Koki Kameda and Pongsaklek Wonjongkam from rematching in Japan earlier this year. But there’s one big reason why Rizin probably won’t be able to get Mayweather to participate in a meaningful boxing match…


Mayweather received at least $100 million for his last fight and it represented a good investment because 4.3 million people purchased the pay per view. The fight against Conor McGregor made somewhere in the region of $600 million.

The global pay per view audience for a fight against Tenshin in Tokyo on New Year’s Eve would be tiny. The kickboxer isn’t a big name outside of Japan and, even if he was, there is nowhere near enough time to set up the sort of publicity tours required to promote a successful pay per view.

That means either Rizin are going to pay Mayweather the going rate for an actual fight, and splash out $100mn or so that they have no chance of recouping. Or Nobuyuki Sakakibara is going to pay him significantly less to participate in an exhibition or sparring match that requires zero preparation and poses no actual risk.

Mayweather has already appeared on a WWE event so there is precedent for him getting paid to participate in scripted shows. Whether or not this will please the fans who are likely to flock to the Saitama Super Arena in droves remains to be seen.

Rizin has promised the world a Floyd Mayweather fight on December 31st. Sakakibara must now try to deliver exactly that, but to do so he will need to complete the most complex deal in combat sport history. He has less than two months to get it done.