When it comes to data analysis, counting things is fundamental. DAX includes a default count aggregation, as well as the COUNT, COUNTA, COUNTX, and COUNTAX functions. However, there will be situations where you'll desire a counter that operates differently from normal count operations. In these circumstances, you'll wish to have more of an index that starts over when you're given specific criteria. A good example of this is consecutive wins. Your consecutive wins count increments by one for every game that you win. However, once you lose a game, your consecutive wins count starts over. Thus, you can imagine a dataset that holds a historical record of wins and losses. A counter that keeps track of consecutive wins but starts over once there is a loss would be necessary to determine the longest streak.
This recipe implements a counter...