Change is one of the key teachings that I stressed in the practice of Tai Chi.
To understand change you have to know your form inside out. However, blind practice will not do. You have to practice your form with knowledge of what you are practicing.
Step Forward Seven Stars (上步七星) is a technique that on the outside looks like you are stepping forward to perform an X block. However, this makes no sense if you consider that Tai Chi is a sophisticated art to begin with.
The way we do Step Forward Seven Stars (上步七星) is slightly different from how the typical Yang stylist would do it. Below is a photo of how most practitioners do it. Notice how both wrists are close to each other.
The way we do Step Forward Seven Stars (上步七星) is to have the right arm more forward. Thus, the right wrist is further forward of the left wrist. The example below shows Grandmaster Dong Yingjie demonstrating Step Forward Seven Stars (上步七星).
There are different ways to use Step Forward Seven Stars (上步七星). In the clip below I was showing Paul the basic principles of how to use the technique.
Then there is the question of how to change from there if attempts are made to counter the initial attack.
If you apply Step Forward Seven Stars (上步七星) properly you can easily change from one technique to the next.