Would you be an atheist if science and reason wasn't supportive of atheism?

[Vincenzo Vinny G.]

-Or- you could explain how it is.......you know, engage in that discussion you desire.
(you seem to be missing a key variable in your question btw)

Pro-tip

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Along one interpretation, in the hypothetical granting the universe, and given god or no god, the probability for both is exactly 1 for 1.....because here we are. That's the trouble of assigning probability to an event that already happened.
Along another interpratation, granting the universe but not taking god or no god as a given, we weigh the evidence and reflect upon how that might compell us to modify our beliefs, insomuch as we have them - whatever they may be.

In one scenario, it's useless unless we take the very idea we wish to explore as a given (which is how we end up with parity between them-it was smuggled in before any computation was done-), but we can't really do anything else, as assigning a probability to a concept like god is absurd - give it a try. In the other, we have overwhelming evidence for one side of the coin - and yet people have failed to modify their beliefs. Not all of them, mind you, the RCC famously decided that "evolution was a-ok", recently as one example.

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Did you come up with this yourself or did you copy and paste it?

Along your first interpretation, it's absolutely false. Consider this analogy "In the United States, the probability of winning the lottery is exactly 1 in 1. But for Bob, because, well, there Bob is with his winning ticket."

That's not how probability works. In fact there's a name for the kind of fallacy you are using here. The Texas Sharpshooter Fallacy.

It's when someone fires randomly at the side of a barn, and then draws bulls-eyes around the bullet-hole and calls himself a sharpshooter. Ie, you are using data that is not meant to give us proper probability.

That was my pro-tip, by the way.