I took the time to post how they approached the problem of definition. The purist definition was included in an earlier post. It would exclude Muirfield, Royal Portrush, and Royal Lytham and St. Anne's.
I actually think the discussion was helpful as far as showing their reasoning for not accepting the purist or absolutisic definition. Without considering the definition and showing a rationale for rejecting it, their own criteria, which are turf, terrain, and weather, would be subject to criticism from a purist point of view.
They discuss other issues in the chapter before moving on to the courses they define as true links. In reading the chapter, I don't think they seriously entertained out and back routing. If so, they would have had to exclude four links courses in County Donegal, aming many other absurd exclusions, like both of the Barnbougle courses in Tasmania.
I hadn't looked at the book for a couple of years. This thread got me to take a look. I ordered a second copy to keep up in Seattle, where I stay part of the time.
Charles Lund