Here's something I never thought I would post: I don't know what the ratio is, but almost every one is a large date.
Based on your pic what you think is a doubled die or (DDO) is actually MD (Machine Doubling).IMO Dave
I'm confused. If you knew it was a large date then why did you ask in your post title if it was a SD? And if you wanted to know if it was a DDO, why didn't you ask that instead?
not every 1970 S is a DDO or small date. otherwise, they'd be a ton of them out there and not be valuable at all. Could send it in to grading just to find out anyways ...