Tai Chi Chuan is an invaluable asset as a supplement to any fighting style as well as a viable stand alone system. Its push hands concepts of yeilding, adherence, softness, spontaneity, and rejection of brute force, are excellent methods for developing a greater awareness. It really aids in the understanding of other systems as well. For example 7 star mantis has very similar concepts with adherence and yeilding to gain attack advantage. The underlying goal is to be able to feel the attack before it occurs. The reasoning behind this is that if you can strike as your opponent is "thinking " attack, just at that moment before he initiates, it will quite difficult for your opponent to defend. This is due to the fact that his/her mind and/spirit(intent or will) is so presently focused on attack, the thought transferral to defense will be too late to stop your attack, at least in theory, and Ive seen it in practice. most of these styles are lost in the west due to the impatience of students who want all the skills right now. The stance training, and relentless basics, and breathing exercises of this system are either discounted as false or mystical, or given up on by students because of the length of time it takes to grasp them. Still for those who earnestly seek martial studies this type of training is quite useful if not necessary for a survival minded fighter.