Come on, I didn't invent that cheese planet stuff so you can weasel out from improving yourself by looking what illogical fallacy means. You wrote the same stuff, just in different words.
OK, let's have another example. For simplicity of the example let's say there's been only 99 monotheistic religions in the history of mankind. (Note: These are not mathematically correct, but it won't affect the point and will make it simpler, plus I'm just lazy to calculate)
Now we ask a question - "Is there a god?" - and not specify any particular god - just if there is any god. All right, the probability for there being a god would be 99%, 1% being there is none.
Now we ask - "Is there an islamic god?" - meaning what are the possibilities for just that one particular god being there. Percents would be 1% for yes, there is an god. While 99% would be there isn't an god.
Do you see the "awesomeness" of "I can't prove, you can't prove" logic there? Wrongfully often titled as common sense. Of course theres been thousands of religions and beliefs in world so the possiblity for there not being a god would be 99.9999...% and rising for each new religion. But for islamic (and christian and pastafari among the others) god 99.9999...% Gosh, I hope there's no concept of christian hell in most religions...
*gasp* What if the god is outside of the 99 religions range? What if god is this guy I just imagined, or saw at TV? (Why I have feeling that you, an agnostic, when talking about god you think about this jolly good bearded white sheet god with low masculine voice with a little echo?)
In short: Not the 50% chance with your flawed logic which disgraces the capability of human brains. Or can you say every lotto number from this day to 1322 (not 1321!) years into the future will be same because there's a chance for it? It can be or it can't be.