UnholySanctuary, I think we at least have rules (?) as to when an S is pronounced like a Z for the words we didn't change. It seems if it's at the end of a word and there's a silent E afterward, the S is pronounced like a Z. For example, 'cheese'. However, people are VERY stupid, and becuz of this we DO have some...highly unneeded exceptions like 'goose' which USED to be spelt 'goos' till some-one decided to add a silent E (likely a misspelling)... Oh, and if it's a pluralizing S, its pronunciation is dependent on whether the previous sound is voiced or not (example: 'kits' versus 'kids').