My humble opinion. . . in a controlled environment (ring or cage - definite bounderies), an experienced TKD practitioner will probably have one chance and ONE chance only to connect a good kick (or a series of kicks) and possibly injure or knock-out a polished boxer. If unsuccessful in that ONE moment, it will be very difficult fro the TKD to defend as the boxwer will cut the range, fight inside and bully the TKD from escaping. The boxer will probably hit the mid section first (a definite weak point for a TKD practitioner), then immediately go upstairs. If the TKD practitioner tries to escape, all the boxer has to do is stick close or bully by blocking and shoving the tkd practitioner back to a defensive position and continue punishing the TKD practitioner. I see this type of fight over in less than 30 secs depending who makes most of his opportunity. But I will place my bet on the boxer because of the probabilities.

If the fight, however, were outside of a controlled environment, the TKD practitioner may have more chances as all he has to do is back up and deliver a kick or move forward with a kicking combination and run away to china to create distance to allow for a second kicking combination. Here I favor the TKD artist.