Craig:
When you start mentioning things like a 19th hole, I start to think of other interesting architectural ideas!
First of all why have a 19th hole, or a 20th, 21st, 22nd etc? To make anything like that work well there has to be a reason for it and generally a very good reason--and it has to work well somehow, for whatever reason!
I think, in certain situations--ie a really good site with more than 18 good golf holes sites and possibilities and a need or any good reason to use them well--the possibility of having more than 18 holes can be interesting--if their use is interesting.
This can get into the concept of "courses within a course" and it's a concept which is fascinating and very much "outside the box".
In it's best form it can create some very interesting "courses" (within a course), where, for instance, there may become a number of ways and a number of routing progressions one can play a golf course!
And if, somehow, this kind of thing--"courses with a course"--could be done in such a way where one routing progression (or course) would become recogizable and valid without the other "courses" becoming even recognizable to the golfer, you really might have something--something very interesting architecturally!!
I have a lot of different phrases for things and this one I call "Rorcshach" architecture!!
Like a Rorcshach test if you squint and look at it you might see a women's face pointing right, but if you squint again and look at it you might see a duck pointing left!
Theoretically, and if done well you might have a golf course that can be played many different ways and when playing it one way, the other ways would not even be recognizable.
I think it can actually be done, given the right circumstances with only 18 golf holes but if it works with 19 or 20 or 21...etc, so be it!!
Say, for instance, a golf course you could play a different way for every day of the week and not even see the other ways or days while doing it!!
George Thomas experimented with this and it even appears he may have done it well but it was not sufficiently recognized, for apparently other reasons.
It makes me wonder about Thomas! Many of the holes and courses he did were very creative but he may have been more creative than we realize--possibly the most creative ever!