The first time I tried to use this argument, my test subjects switched from exact 0 to a ridiculously low percentage intended to mean basically the same.

Now I notice that your comment reveals that I may have committed an inconsistency with respect to a chain of comments I wrote before on the same topic.

This has me thinking. Eliezer said,

What would convince me that 2 + 2 = 3, in other words, is exactly the same kind of evidence that currently convinces me that 2 + 2 = 4: The evidential crossfire of physical observation, mental visualization, and social agreement.

I guess a fully consistent position would sound like this: "I'm very confident that the traditional description of God conflicts with itself, which makes the existence of God extremely unlikely in this universe, but of course there's always some likelihood that this universe doesn't work the way I suppose it did, or logic has a loophole that nobody has seen before, or omnipotence doesn't really care for impossibilities, and as a result God is real. But so far this doesn't look like the type of universe where that would happen."