I think someone who is good at judo for example would win most times if they got hold of their opponant,Im saying this as my friend did this for years,there were two clubs in the sports centre,the other just played at it,but my friends worked hard at it.Groundwork was high on the agenda,as most fights end up there,and their strength was high.If a person is a serious groundwork fighter then if they get hold of you its curtains,you will be unconcious in minutes.But knocking someone out with a punch isnt as easy as some believe,only if you practice all the time with punching combos,and even then if you connect correctly,and this can only come with years of practice,and i mean hard practice,not just going through the motions that most iv seen seem to do.Or get lucky.Kicking is the same,you have to practice hard and over a long period to become adept at it,the point made about a punch being more direct and easier is a good one,but if you keep your kicks below waist hieght and practice like you would a punch,there is no reason why it cant be as effective in a given scenario.But as i have said,im talking about seriously hard training five or six days a week for at least a couple of hours each day.having the heart for it is a lot of it too,mental attitude can make or break a fighter,even if they have the best technique in the world.But what most seem to forget is that if your on the recieving end of a good solid fast and powerful punch,you will go down too,iv seen streetfighters who have more speed and power than most martail artists,and they have the aggression to back it up.Martail arts are not like in the films,its just another way of fighting that might be different a little to a streetfighter.Some of you will have seen documentary films of masters and high grades in a martail art having a bout,and they just let fly,similar to streetfighters,but if trained properly they might be a bit more acurate and powerful,and maybe able to dodge a few incoming.
Train hard and long enough,and you might be able to effectively defend yourself.Go to a two hour class two or three times a week,and your just pretending and would probably get hurt in a real situation.
If a good boxer had groundwork experience,then i feel he might be very difficult to beat,thats if you could,just like a kickboxer,these are the hardest styles i would say and the most effective.
But then it comes down to attitude too,if you dont have the fighter attitude,you wont do well no matter what you practice.Some circumstances granted,but a real nutter intent on putting you down? Probably not,you need to be able to stop these or you get hurt.How? by constant and hard practice everyday,i dont think many do that,so are kidding themselves,unless they are streetfighters anyway,and just want to expand on it.
So to answer your question,its hard to say,but if your a hard training boxer or kickboxer,then i think if you connect before a hard training grappling martial artist gets hold of you,your probably going to win,but if a grappling fighter is handy with punches too?? who knows?I suppose it doesnt matter what style you do,if you get the first few in then your chances are better than the other person,unless he is a naturally hard person with a jaw of steel,then your f@@@ed anyway