Birdie pins: 1, 2, 7, 11, 13, 15, 16. But many of those pins are the standard Sunday pins.
Obviously, the 16th is a harder hole when the pin is anywhere on the "upper shelf".
I think the pin on 4 was completely new, and the players seemed totally bewildered with how to play their tee shots and putt the hole. The pin on 18 was new, too, and players were having trouble reading the putt.
I think they moved up the tees on 3. That was enough to embolden El Tigre into his fatal mistake.
Both the 5th and 14th pins (on all 4 days) are always difficult, it seems.