So what do you shoot on avg? My guess is that Brooks, not seeing the course, he shows up at the range and hits a few balls on the course that I mentioned is going to fire mid to upper 60's from the tips. And, he could go low 60's(he definitely would after playing it a couple times) he is going to destroy the par 5's and eat up many of the par 4's and they hit the ball so far that he could hit irons or 3 woods off the tee(to stay out of trouble). I believe the course record is 61 or 62 from the tips. So, Brooks is better than that guy I am sure. But, that is knowing the course and a one rounder. But, it is hard to go much lower.
Let's say Brooks shoots a 66. The 12 handicapper would need to fire a 91. But, the 12 handicapper is going to have to putt everything and count all penalties. No gimme's and you have to count your strokes. No rolling the ball for a better lie, etc.
12 handicapper is going to be hard pressed to beat him.
If I give you 7 a side, you need to be ready to shoot a 80 and play by the rules. That means you are probably single digits. 80 might not get it done. A good D1 golfer can go in the mid 60's on that type of course, from the tips.