I bet the 40% is about right. I wasn't even close to being in that 40%. My attempts to just quit couldn't keep me sober until noon. I also agree that AA is more of a support system with a religious bent than it is a cure, so talk of success rates in AA is a little goofy, like trying to measure the success rate of a church. I wasn't a God guy so I didn't think AA would be for me but I ended up liking it. If you aren't too think skinned, you can believe whatever you want in AA. The good part is you have instant friends, not something easy for me to find, as well as sober softball and pot lucks. I thought for a while that the people in AA weren't good enough for a smart, sophisticated guy like me, but it turned out nobody is really good enough for a smart sophisticated guy like me, so the AA folks are as good as any.