These are common standards to follow in modeling our balance sheet items. BASE is an acronym that stands for beginning add additions less subtractions equals end. The corkscrew concept refers to the way in which the base setup is connected from one period to the next. In the following screenshot, we will see that the closing balance from one year is carried forward as the opening balance of the next year:
We notice that the movement is from the opening balance, which goes down the rows of the first year to the closing balance, then back up to the opening balance of the second year, then down the rows of the second year, and so on. This creates a corkscrew effect, as seen in the following screenshot:
