tyson cant do much when he meets up with an opponent that can actually take his hard punches. like his fight vs evander. Cap wont really be effected by his hits and even if there are 50 of tysons. they simply cant really harm him.
yes no problem. if we bring tyson into the comics world, he will be perhaps slightly more skilled than the average street thug but thats about it. he is still just a human who simply can punch harder than the average joe. lets not forget that mike tyson fought people for like 8 rounds before he knocked them out. lets not forget he faced guys who could take his punches. he was also knocked out. Captain america can just stand there and take all 50 of them punching him until they get tired and out of air. now throw in his peak human speed, strength, by far greater skills. even if tis boxing skills are still playing huge part in dodging and fighting the right way. he will curb stomp 50 tysons and 100 tysons. you cant compare a real life human athlete to comic book hero standards. specially someone like cap who is between a peak human and actual super human by feats.
again, mike tyson went for long long rounds with many boxers before he knocked them out. there are boxers that also took his punches and ate them. he is just a boxer. sure a strong one, but compared to the comic book world standards he will be just another big street thug and handled easily by any street leveler. even 50 mike tysons hitting Cap while hs is just standing, will be like 50 5 year old kids hitting you while you are standing.
of course. its not even a contest. 50 athletic boxers vs the super soldier cap? speed, strength, skills, reflex, durability, stamina... its not even funny how hard they are going to get stomped.