Well, as I said, I completely made up the numbers to illustrate two things based on your query:
1) The base SP gained is split up into the number of people in the party regardless of whether you're in range or not
2) Your bonus is calculated based on how many people are in bonus range of you. If no one is, you're SOL.
This was presented as a counter example to the idea that it's based off average group rank or something similar.
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