The Distinctive Techniques of Hsing-i-ch'üan with Taikiken Pages Part 2 by Kenichi Sawai

Relations between opponents in Hsing-i-ch'üan are especially distinctive in three respects. First, since there is no way of knowing what kind of attack the opponent will try, Hsing-i-ch'üan does-not prescribe such things as maintaining fixed distances and employing kicking techniques. Instead, the individual must always move toward his opponent and counter his moves as he attacks. Second, since defense must always be perfect, in Hsing-i-ch'üan, one arm is always used for defence purposes (it may be either the mukae-te or the harai-te method; see p. 34 and 60). Third, there is no strategy, and no restraints are used in Hsing-i-ch'üan matches. Since the individual's body must move naturally, easily, and rapidly in conformity with the opponent's movements, there is no time for mental strategy. Nor is there any need for restraining the opponent with one hand while kicking. At all times, maintaining a perfect defense, the person must conform to the motions of his opponent. This, as I have said, leaves no time for mental strategy. 

Sawai Sensei showing his Taikiken Hai exercise in Meiji Jingu park, Tokyo, Japan