I work out the risked resource per target and then determine the...

I work out the risked resource per target and then determine the ratio of the total risked resource each is to work out how to weight each individual gpos into an overall figure.
I'd be interested in how you get to 17% as I'm interested in other methods people use that might be better than my own.

I agree that we're looking for runs on shows to freecarry given we haven't had a BESBS run up and the SP will dip if the shallower targets aren't charged but they're also fault migration dependent and the step down from 19.8% of 1112mmbbl to 12.6% of 835mmbbl isn't as horrible as it sounds given it's entirely plausible that the fans are simply very effective traps with no shallower migration and even though the shallower targets have the better probability, the lower targets have the better potential resources.