OK, this question gets brought up a lot and as the resident JKD guy, Ill chime in. There are many factors to this question but it boils down to the ground game. You cannot take Bruce in his "Prime" and compare him to a fighter of today. Bruce against a fighter of equal weight, yesteryear, would be very dominant. His Judo, wrestling and sambo were very very good. Its like putting Royce Gracie against Jake Sheilds. Its just a different game now. To be fair, if Bruce was young today JKD would look completely different. Bruce would probably be a student of Eddie as well as teaching stand up or MMA. The fact still remains that he is the single most influential figure in martial arts history. With out Bruce most of us would not be here today.