Pine Valley's #1 was intentionally designed to serve as a good 19th hole. The model for it in that vein was Hoylake's #1.
You can read the actual documentary evidence of that at Pine Valley on the "Splendid Isolation" thread on post #128. It comes from Crump's close friend and constant playing partner, Father Simon Carr. There will be a bit more about that and its model from his other close friend and constant playing partner down there, W.P Smith.
As for what happens in play-offs, particularly big ones (lots of players) really is very interesting. I know, as I've been in a bunch of them on that hole.
One of the most remarkable playoffs I've seen was as a spectator of the play-off in the finals of a Crump Cup (two man). It ended there and the guy who lost hit one of the gutsiest and most agressive approach shots I ever saw. Had he hit it just a foot left he probably would have birdied and won right there but alas his shot was about a foot too far right and he was down the bank and almost in the woods!
That player, Philadelphia's Chris Lange, probably knows Pine Valley and it's intracacies as well as anyone. He had a 9 iron in there and he is an aggressive player anyway. He hit his approach right at that infamous mid-right Sunday pin. He knew as well as anyone you just can't land right of that pin. He landed about 2-3 feet right of it and after a stop and trickle his ball slowly filtered off the green and tumbled down the bank and almost into the woods!
His opponent, New Jersey's Billy MacGuiness had already hit the perfect approach shot about 15 feet left pin high!