Mark -
I really like the phrase Brent used on another thread, i.e. the geometry of the course. And when you ask about ill defined architecture I think about courses that have (and allow for) a fluid geometry -- the shot-making angles and the relationship between those angles in both two and three dimensions can and do change, while still allowing the course to be playable; and this fluidity can be the result of either the wind, the turf conditions, the golfer's choices, or a combination of one or more of those three elements. And when I define/describe it like that, a type of course immediately comes to mind (for me, from photos only), i.e. courses like Wolf Point, Ballyneal, Sand Hills, and to a certain extent courses like Seminole, NGLA, and Old Macdonald. Needless to say, width allows for more fluidity in a course's geometry, as does a lack of trees etc. On the other end of the spectrum, a course I like quite a bit, i.e. Harbour Town, has wonderful geometry, but it is much more of the fixed rather than of the fluid kind. (I think Pete Dye in general goes for more of a fixed geometry at his courses, but he sometimes -- and intentionally -- fools/confuses golfers about this by ladling in essentially meaningless hazards and features so as to suggest fluidity where none exists, and thereby to get those poor tour pros 'thinking'.) Rough you can play out of, greens with open fronts, undulating greens, not overwhelming length, elevation changes (even just bumps and hollows) and canted fairways of course also expand (or have the potential to expand) a course's geometry. The Old Course seems to have, and perhaps is unique in having, all the key elements needed to foster/create fluid geometry.
Peter