Maybe I'm Dumb When It Comes to Something Like This, But...

I can't figure this thing out. It's a mind-reader program, and it's kind of disconcerting. Maybe one of you out there has a better grasp of mathematics or programming and can explain how this works, because I sure would like to know.

Update! I'm a dummy. Read the comments below for an explanation of how it works after you've played around with it for a while. And I've been caught by this one before. You'd think I would've learned the last time.