The OPEN-Close model includes all the elements of an interaction with a girl that create a deep and meaningful relationship with her. The question is when and to what degree do you use them?
Generally speaking, OPEN-Close is sequential. This means that after opening, the conversation should typically be premise heavy, and, as the set progresses, evaluation and later narrative play a relatively more important role. The following chart shows how much of each element you should have at any point during your conversation:
The idea here is to begin to build an intuition about how your game should look throughout the interaction. Notice that generally your game should include some degree of each element at any stage in the conversation—avoid neglecting any one area for long.