64 for me at Merion.
I went out with the game plan of avoiding bogeys or worse on the holes I knew were hardest for me, so as to make any birdies count, not expecting any birdies really, but hey, a dame can always hope . . .
Well, I had at least 1/2 dozen 62-yard punch shots that were almost holeouts. So those became easy birdies, even for my putter. Plus a couple more birdies from farther away.
The game plan worked, except for the double on #15, though I thought I was playing that one safe, too. Oh well.
GLTA