When I took this course in 1960's it was state of the art. It is a little different today but the basics will never change. That said if you study this little 40 page tutorial you will have the basics for Z matching far beyond the one line continually misapplied. Many an expert will tell you that one line and stop. It is not meant to be the definitive statement but rather the teaser line that draws you into the study so either ignore the post or be prepared to study at least the first 5 or 6 pages. If you read the first page and say "that is what the other guy said." you will miss the point. It is the lead in not the final statement. So for the brave download and read the document.