True, but Google has a long tradition of not revealing its internal processes. That's because whenever people thought they understand how it works, they tried t

True, but Google has a long tradition of not revealing its internal processes. That's because whenever people thought they understand how it works, they tried to game it. That's why there are hundreds of spam comments that get through recaptcha on my blog each month (and I'm nowhere near a popular blogger). I imagine they don't want people trying to game this system.