The Taiji classics warn against creating a situation of mutual resistance, also called, less clearly, double weighting. What is mutual resistance? A simple illustration would be when in pushing hands one partner is pushing and the other is responding with a Peng that causes the pushing partner to feel a push against his push and causes motion to stagnate.
One important key to understanding how to resolve this situation of mutual resistance is the word “mutual” (or the word “double” in double weighting). Take the word mutual as an indicator that either partner can resolve the situation because it is mutual. The first partner to act to resolve the stagnation will gain a significant advantage.
The Taiji classics provide the solution to resolving a situation of mutual resistance. They say that when my opponent is Yang, I become Yin. If you are pushing your partner and you feel a push back, it means that both of you are Yang. Either partner can resolve the situation by turning Yin. The pushing partner can turn Yin by coiling over the opponent’s wrist, applying pluck and leading the opponent’s resisting force into emptiness, which likely will result in the opponent being uprooted. The partner being pushed can turn Yin by coiling over the opponent’s wrist, applying pluck and leading the opponent’s pushing force into emptiness, which likely will result in his being uprooted.
Another situation of mutual resistance can occur if one partner attacks high with backfist and the opponent meets it with Fair Lady. The first to change tactics to apply Step Back and Repel the Monkey will gain the advantage.
An astute practitioner of Taijiquan can attempt to create a situation of mutual resistance in order to exploit it. A sudden push can to lure out the opponent’s resistance can be turned into a sudden pluck to exploit the resistance. In the classics this is called “suddenly appear, suddenly disappear.”