What would be fair hybrid rules for boxer v mama fight ?

Now remember I'm talking about a 1 off fight not something where these guys are going train for ages in new areas or change sports. They fight and go back to their respective sports. So what would be fair for both guys ? I would think some kind of 6 ounce glove that can be used to grapple. Allow grappling on the feet by not takedowns. No submissions. Elbows are allowed but not kicks or knees. Fight is in a cage. Is that too much in favour of boxing ? I dunno. Remember the top mma guys have trained boxing for years, so imo the rules should be closer to boxing than mma to get a good fight. TBH, I'd have the same rules as you have. Boxers often train in various forms of grappling to be able to work on the inside but yeah, take downs being against the rules make sense because guys with longer wrestling experience would just pummel boxers on the ground. The gloves can work well for the MMA guys, claw back some advantage. IMO, I say, allow kicks but no submissions. Still keep it in the ring but make the rounds similar to UFC limits, so for a champ bout, five 5 minute rounds.

This isnt the 1st time it would happen

Fair would be to alternate rules round by round... Or to allow at least leg strikes every other round.. This is not about fair though, it's about getting $$$$$$ It's a circus sideshow...

That's hard. I guess very close to kick boxing? Every MMA guy is trained in every block and punch a boxer throws they train with top boxing coaches all the time and spar pro boxers. No boxer trains with kicks or elbows or with MMA moves, do you really expect a boxer to learn stuff he has never ever practiced ever . while the MMA guy has trained for many years to box . You only got one area that is the same and thats stand up boxing , all the crying is about the boxer being so superior .

No choke holds

That's hard. I guess very close to kick boxing?

Basically just meet at the middle with the kickboxing rules. You could have some very interesting matches between MMA guys who can kick but aren't exactly great kickboxers with different styles of boxers. For example I can see lesser boxers beating MMA guys at K-1 ruleset and some elite boxers failing to beat some of those same MMA guys. Boxers who use a lot of defensive out of range lateral movement and like to fight on the outside for example would struggle with kickboxing range and could get their legs chopped off, while pressure fighters with power would walk past the kickboxing range and bring the fight to the MMA fighter at the boxing range. For example I can see Maidana beating Conor McGregor under some caged muay thai or K-1 ruleset but not Floyd who would get kicked by Conor and his philly shell wouldn't work. GGG's style would also translate greatly into any combat sport with strikes involved because he would easily cut off people and force them to fight at his preferred boxing range + power and chin are even more valued in MMA. Then you have boxers who used to train kickboxing in the past like Povetkin or Huck who would probably murder just about anyone in the UFC in a purely stand up fight. Shoot boxing rules are another interesting middle point where you're allowed to use standing submissions as well as throws but there's no ground game involved: https://en.wikipedia.org/wiki/Shoot_boxing

I used to watch K1 on Eurosport, and i enjoyed that form of combat sport way more than MMA! I think K1 rules would not be 100% fair, but much easier for a boxer to adapt! If you can walk and run, i am sure you can learn how to kick!

MMA fighters fight a lot of stand up, the boxing training they do is practically the same, boxing training is nothing but punches. There is no area of boxing that allows anything but punches with the knuckle part of the fist, MMA has areas that are the same as boxing. In my opinion a MMA fighter is more suited to boxing than a boxer is to MMA. Its up to the combatants to agree one way or the other as there is no fair deal for a boxer inside a cage allowing anything other than fists.