You referred to the AI as "HE" in the last paragraph. Nice TRY AlphaGo! You almost passed the Turing test.
Seems to me you could "easily" solve all these types of games with a relational database. If Google can index and archive millions of web sites, and poll that data and respond to web queries in fractions of a second, why couldn't they develop a database of every possible state of the board, and simply traverse that like they do the database of websites? I know that wouldn't be AI in any sense, just a machine finding the next most likely state, but it seems to me that Google has the resources at hand.
They couldn't do that because a Go board has 19x19 intersections, each of which can be either blank, or have a white or black stone on it. This gives a grand total of 3^361 possible configurations before we consider the actual configurations that are legal, which is "only" about 2*10^170.
It's impossible to convey just how stupendously enormous that number is. It's far, far bigger than the number of elementary particles in the universe. Actually, if every elementary particle in the universe held its own universe inside it somehow, then the total number of nested particles would still be great way off from this number.
So no, Google definitely does not have the resources at hand. God himself doesn't have the resources at hand. Of all the ways you could have a computer "solve" the game of Go, this one is definitely, capital-I impossible.
From what I "understand", Google's "solution" to the problem is basically self-evolved software. While neat, it doesn't give greater fundamental insight into intelligence or estimation or strategy. It's basically a black box that works, but we don't really know how.
1 light year is basically 10^16 meters. 1 angstrom, the length unit for light wavelength, is 0.1 nanometers, or 10^-10 meters. Ergo, 1 light year is 10^26 angstroms. Space is believed to be 10^10 years old, and therefore probably 10^10 light years in diameter, or 10^36 angstroms.
So, the volume of known space, measured in *angstrom units*...is about 10^110.
This might be hard to answer, but I would imagine that each successive move would temp down the probabilities significantly. I don't know if this approach, if possible, would be better or worse than whatever Google is doing, but would it even be feasible to factor this in to the late-game moves where options are much more limited?