David,
You raise a great issue and it's actually one that causes more headaches for me when we do these lists than anything else I ever do at Golfweek. Once we have all the information in place, producing the ratings is easy; it just takes a click of the button. But editing the final lists and checking the proper attribution of credit are very complicated.
In part, as Wayne alludes, the limitation is space. We have to fit onto a certain page space. But we also can't sacrifice accuracy. Bob Crosby's rule holds true -- credit the original architect, plus subsequent ones where they've made significant routing changes. The problem comes when there are so many intermediary tweaks, what counts as routing change (Maxwell moving ANGC's 7th and 10th greens; RTJ Sr. shifting the 10th and 11th don't quite qualify, arguably). When Pete Dye reroutes Brickyard Crossing or Fazio reroutes Pinehurst No. 4, that's easy. It's when we get to total redos of an existing and preserved routing that I really start getting headaches. I'm not sure I can be as consistent as I'd like because there are so many different circumstances.
Obviously, a list published in or as part of a book will be more comprehensive than a list such as we produce. But even if we can't be comprehensive (i.e. every major change at ANGC) we can at least be accurate.
For example, we give RTJ Sr. renovation credit on Oakland Hills because his work on the existing routing completely changed the bunkering and the strategies of the holes. Tom Fazio's massive renovation of Quail Hollow didn't touch the routing but put an all-new playing surface down on top of the existing one. Yet in the case of restoration, we basically leave off the name -- thus no mention of Ron Prichard for bringing back Franklin Hills. But when Doak redoes Atlantic City CC and adds some holes and combines other elements, we do give him credit, though in that case we kept it as a Classic whereas with a more extensive such renovation (Brickyard Crossing) we'd call it Modern. In the case of Sea Island GC-Seaside Course, it's easy to call that a Modern, since Colt & Alison's 9-hole layout from 1929 was joined in 1970 by Joe Lee's nine, then all altered by Fazio.
Keeping track of all of this is pretty hard, but it is important to have some guidelines. And then Wayne Morrison ruins everything by telling us that Toomey didn't actually "design," he just partnered on construction with Flynn. Oh well.
Basic rules of thumb we follow, in priority:
-list original architect of the basic course that exists today;
-list subsequent architects who contributed to the rerouting of more than two holes (if that can be determined);
-list subsequent architects who contributed to major modernization and alteration of the fundamental character of the golf course (RTJ on Oakland Hills, but not Maxwell or Fazio at ANGC).
Always keeping in mind to keep it simple and readable within alloted space.
Note: moving a green isn't really counted as "re-routing." We save that for actualy moving entire holes-- such as the Fazios did at Inverness or Oak Hill (for better -- or much worse!).