Originally posted by Wind&Mountain
if i were to see a tai chi practitoner and a muy thai practitioner each with say 3 years training i would put my money on the muy thai fighter(hands down).
advance the training to over ten years and i would put my money on the muy thai fighter hands down.
advance the training to over 20 years and my money goes for the tai chi practitioner hands down.
First, maybe. Take an "average" MT person and an "average" TJQ person who's trained the martial applications, put them each in a self-defense situation, and I'd give pretty much the same odds to both.

Second, I disagree. As you noted, MT is brutal, and someone who's been practicing for 10 years may well be past his/her peak and pretty beaten up physically.

Third, I agree, but mainly for the reason I stated for the second example. 20 years of dedicated MT will be pretty hard on the body.

Note: I picked a self-defense situation rather than a MT vs. TJQ ring match to level the field, since MT participants train to compete in the ring.