Jonathon,
Taken from the 1996 edition of the book;
"0-A course so contrived and unnatural that it may poison your mind, which I cannot recommend under any circumstances. Reserved for courses that wasted ridiculous sums of money in their construction, and probably shouldn’t have been built in the first place.
1-A very basic golf course, with clear architectural malpractice and/or poor maintenance. Avoid even if you're desperate for a game.
2-A mediocre golf course with little or no architectural interest, but nothing really horrible. As my friend Dave Richards summed one up: “Play it in a scramble, and drink a lot of beer”.
3-About the level of the average golf course in the world. (Since I don’t go out of my way to see average courses, my scale is deliberately skewed to split hairs among the good, the better, and the best).
4-A modestly interesting course, with a couple of distinctive holes among the 18, or at least some scenic interest and decent golf. Also reserved for some very good courses that are much too short and narrow to provide sufficient challenge for accomplished players.
5-Well above the average golf course, but the middle of my scale. A good course to choose if you’re in the vicinity and looking for a game, but don’t spend another day away from home just to see it, unless your home is Alaska.
6-A very good course, definitely worth a game if you’re in town, but not necessarily worth a special trip to see. It shouldn’t disappoint you.
7-An excellent course, worth checking out if you get anywhere within 100 miles. You can expect to find soundly designed, interesting holes, good course conditioning, and a pretty setting, if not necessarily anything unique to the world of golf.
8-One of the very best courses in its region (although there are more 8’s in some places, and none in others), and worth a special trip to see. Could have some drawbacks, but these will clearly be spelled out, and it will make up for them with something really special in addition to the generally excellent layout.
9-An outstanding course – certainly one of the best in the world – with no weaknesses in regard to condition, length, or poor holes. You should see this course sometime in your life.
10-Nearly perfect; if you skipped even one hole, you would miss something worth seeing. If you haven’t seen all the courses in this category, you don’t know how good golf architecture can get. Drop the book and call your travel agent – immediately."
Tom Doak
TK