listen, one thing that clouds the waters of martial arts, is that there is a section of the teaching community, who do not believe that what they have to teach is enough in itself to inspire interest in prospective students.
In an attempt to agrandise both their art and themselves, over time, they introduce a few 'shaggy dog stories', involving bolstering their reputation, accomplishments and prowess, along with the superiority of their 'system' or 'art'.

I am not saying that this chap is in that category, but for your own interest, you need to do the following.

1. Get his full name.
2. Get details of what year, and what town he dealt with 10 attackers.
3. Ask him what federation/organisation he fought in professionaly.

Armed with that info, go to your search engine(s) and have a look for independant evidence that confirms his claims.

A guy knocking out 10 attackers on his own would not only have made it to court, but would also have made regional, if not national news at the time.

Professional fighters have records- these records are there to be read. Its kind of their purpose, so they are not hard to find.

Check it out and make sure you are putting your trust in someone deserving of it.

ty for advice, i'll have to look into it. i've never actually heard him claim that, only heard it from one of his friends, could be false info. coz the guy is getting abit slack with his MA, so his friend might want to make him look good so i'll want to learn from him and get him practicing more.

i haven't even asked the question: what do i want to get out of MA?

now i need to know how deadly martial arts can be in a realistic way. how many men may a MA practioner fight at once? depending on his skill level, i need to know how good one may get if he fully dedicates himself to it.

You mean you havent asked it of yourself, or of others?

I am pretty sure you addressed this in the beginners forum- wanting 'deadly fighting techniques' and whatnot. Its ok, if we are honest, practically all of us who looked into MA in our teens off the back of kung-fu movies wanted to be bad-a$$es. The more MA you do, the more you realise how dumb you were

lol, yeah, i love those movies, but then i thought that MA was better than what was portrayed, i mean uc guys taking 2 mins to knock-out the other guy. i thought MA was just a wham! then K.O.

Ugh, you thought wrong. In most cases at least.

Watching the choreographed fights on movies tells you nothing about real fighting. Fight choreography itself changes drastically over time - compare the kung fu series of the 70s, looked fast then but tediously slow today with Bruce Lee and the choreography in the Bourne films.
Most real life fights ie without gloves and headguard take only seconds to be decided (though maybe several minutes extra for the victor to continue to batter his victims teeth in).

That is an impossible question to answer...