With strokes below SSA, points per stroke doesn't matter. At Iron Hill Paul shot 58 and the SSA was ~68.3, so -10.3Throws below SSA doesn't work except for courses within a small SSA range like the examples posted above. Rating points per throw increases as SSA decreases so you have to decide where to make SSA breaks to bundle courses together for stats comparisons. 15 under will always have a higher rating on a lower SSA course than higher SSA course. It's a natural law we discovered with the ratings process, not a factor we fabricated.
At Great Lakes open he shot 45 and SSA was 58, so -13