title: Looking to use ARRAYFORMULA to increment-count adjacent rows containing either TRUE or FALSE
body: <p>I have a dynamic table in Google Sheets that has, among other irrelevant columns, column B that has done various calculations and resulted in either TRUE or FALSE for each row in B4:B500 (the first three rows are headers and summaries).</p>
  <p>What I would like is to be able to calculate in another column (C would be good!) how many TRUEs there have been so far (top down) in the current <em>streak</em> and, when B changes to FALSE, do the same thing, resetting back to 1 at each change in B's value.</p>
  <p>Here is a link to example of my data (sorry, rep&lt;10 so can't just post the image):
  <a href="https://imgur.com/a/vFPelxB" rel="nofollow noreferrer">sample data</a></p>
  <p>Since the actual data is a lot more than ~20 rows and will be updated at least once per day for the foreseeable future, I'd prefer to use ARRAYFORMULA to calculate C rather than having to drag formulae down. Additionally, unless the scripting is extraordinarily simplified, I have a very strong preference for formulae rather than scripts.</p>
  <p>If I wanted all of the TRUEs or all of the FALSEs (or even all within a pre-determined range), I could do that already; it's the dynamic nature of the problem that is stumping me.</p>
  <p>advTHANKSance</p>