I am lucky anuf too study under grand msater clingan in tangsoodo. One of the first things he hade me do was go too other schools in my area and watch theam two see the difrence in our art and theres.I found that in the tkd schools in our area we nothing like tsd. thay use littile or no hands no self defince no ground woork and thear kicked were very looping. You could see theam coming and chabering once they got the kick off it was fast but it was so teligraphed you could stop it befor it got off. I have ben online and looked at many other tkd schools wourld wide and have yet too see one that resembeld tsd at leat the tsd i am taught. There for i dont belive tkd is tsd little brouth, But thean agen you can definetly see tsd influence in tkd.BUt wile it looks the same the tecnique is so very difrent. Dont get me rong i am not insulting tkd in any way i belave I have just seen bad schools and instructors.Hope this helped and sory for the bad grammer