The numbers work out to be the same, I just changed where they were added. The 80 is selected, for instance, because that's what all the constants in the old numbers added up to be. The only difference is that the standard deviation will be slightly smaller in this because it uses a fixed number of rolls instead of rng-ing each separately. Unfortunately I can't PR this separately because the old system violates encapsulation pretty badly. All of the "mechanical" changes are as close as possible to the old system as I could manage, in the sense that their expected values always match up and their standard deviations are usually fairly close to matching up.