This trains the principle of the connecting the spirit and intent, the principle of crossing the hands.
Partners stand facing each other at a distance. Then each steps into chuanzhang on the same side, attacking the partner's throat, so immediately connecting with the partner's arm.
Daishou can connect to the chuanzhang partner practice. If your partner comes in strongly, then continue the movement by pulling.
Rotating chuanzhang can connect to the chuanzhang practice If your partner feels weak then move in and stab again.