Humans are very adept at spotting patterns. We use it in our interpretation of speech and writing, and the recognition of objects and faces. Our personality and behaviour is a set of patterns we unconsciously adhere to. A (daily) routine is a set of patterns we perform regularly. When a routine is upset, the pattern is broken. After a period of confusion or chaos, a new pattern emerges. Even if patterns don't break, they usually evolve. The habits you had 5 years ago will probably have changed into new ones. Maybe they are completely new, but often they are toned down, exaggerated or changed another way.
We can exploit this feature in our characterisation. And use our innate pattern-matching ability to spot games, common traits and hidden links.
It is quite possible, I'm sure, to define improv entirely with reference to patterns. It would somewhat remove it from the practical realities of performing it but be a very useful intellectual and even educational endeavour. If I get round to doing it, you'll be the first to know.