Mark,
Not to fret.
Bryan achieved colossal moron status when we met at Streamsong two years ago.
Bryan.
From just short of the water to the front of the green on # 15 it's 30 yards.
From a little further back to the center it's 50 yards, and
from further back it's 80 yards.
Today, an announcer stated that from 100 yards, it's one of the most evil shots in golf.
You'll notice that most of the Pros lay up to 80-100 yards in order to hit a full shot.
They don't want to get too close for a number of reasons, one of which is that the closer you get, the harder that shot can be.
Hope that helps further your education on GCA and how to play golf