I attended one of Peter Steidlmayer's Market Logic seminars back in the 80s. They say he's changed the method somewhat since then but not in any substantial way. He was building his TPO distributions from 30-minute bars. I'm sure he didn't care a hoot whether any particular 1-tick TPO had actually traded. Good luck with your spreadsheet! Once you get the hang of it, you get a new and different angle on price action. You also see empirical proof that efficient markets and independence are not to be found in the real world. His whole idea is that the markets are always striving to make price and value converge, and never quite succeeding.