Bob Crosby,
Until 1924, holes # 10, 11 and 12 crossed Ardmore Avenue, which was definitely not OB. However, since 1924, no holes cross Ardmore Avenue and it is OB. 1924 was a while ago, so I wouldn't call the change "recently". Incidentally, if you hit your ball across Ardmore Avenue and back onto the golf course on the other side of the road, you are still considered to have hit your shot OB. I've never really liked that, but since it probably happens 3X/year at most, it's no big deal. but if it happened in a playoff for the U.S. Open or a match in the U.S. Am or a Walker Cup...............
Mike Sweeney,
First, I acknowledge that Merion does have a fair number of holes in which OB is a definite factor. I consider #'s 2,6,7,8,14,15 and 18 to be clear examples of that with #17 also a candidate. However, while I have seen (or hit) the occasional shot hit OB on #'s 1,10,11,12 and 16, those are very big misses and/or bladed bunker shots. I have also seen a tee ball sliced so far off #5 that, yes, Ardmore Avenue was its resting place. I have also seen a dead right pop-up off the back tee on #4 that crossed over the back of the 7th green and.......guess what? I did not hit either of those max-errant tee shots, but, in both instances, I was beaten by the guy who did! Realistically, I count 7 1/2 holes where OB is in the player's head and five more where it's possible, but not really a big issue.
Also, the "pond" on #17 in your youth was an accident. In the early 1980's, after the '81 Open, a drain pipe got clogged and, before the then-super could drain the area, frogs and other creatures began to live there and the EPA declared it a bona fide wetland. So, the club was forced to play the area as a hazard for at least 15-20 years until, somehow, they were able to get regulatory relief and drain it. The wood chip path from those days still remains at the bottom of the steps but the red stakes are gone.
FYI, pre WWII, that area was, in fact, flooded every Winter as a skating pond and there was a heated shack on the crest of the hill that was taken down each Spring. The Platform Tennis courts are NLE, as well.