i dont pratice JKD but notice alot of the principals work even if you are trying to use a certian style what is efficent is efficent. i praticed Ninjutsu when i was younger with no teacher (i kno i kno dont yell) but learned alot because of stephen hays books and anatomy books i studied and sparred. i think understanding the body as much as possible can help any fighter. now i pratice southern Hung Gar with a great sifu in a strong style. what i find odd about JKD is that it reflects alot of wisdom in ninjustu, like if im going to fight a ground fighter i should know what they do and how to combat it in order to not be taken by suprise. JKD takes this kinda opinion but with the idea that you dont know who you are going to fight, so you need to know all. the problem with this IMHO is that it is not good to be a jack of all trades while a master at none. i think it is best to train one style hard and learn it's weakness and train them. while i completely dislike ground fighting i realise i may be in trouble if i get taken there, i know a good deal of body mechanics/ anatomy to help me counter this. of corse the best scenario is to use my hung gar to destroy the man before he can take me to the ground.