If you're assuming it's just a matter of taking a simple game like tic tac toe and "scaling up" with program then you are completely incorrect.

It is exactly like scaling up. The exact same principles are programming are in play. Google just has way more processing power and resources than your average TTT AI programmer has access to. Pretending some amazing programming took place shows you know little about evolutionary AI or how it works.

There's no brilliant tactics going on. There are simple rules going on that the "AI" is following. It's pattern matching things that worked before in ways that a normal human doesn't normally identify, because humans by and large play the same games the same way following known strategies. Change that slightly and a human doesn't see it because the basic fundamentals are thereand being played in different ways.

The AI isn't constructing far reaching strategies, its playing as it evolved to play, which is what worked before. The appearance is that there's some amazing strategies at play, but what its doing is not particularly complicated.

Its not placing a piece because it is thinking ahead to some great strategy, its just placing a piece. Later on it may use that piece later if it comes up and people think its doing some amazing strategy because people think things are more complex than they are.

What do you even mean "closed system"?

By which I mean its a game with specific simple rules and that's it. There's no grand strategy in it going on. It's like chess. There's some classic known opening moves, some middle game theories, and some endgame moves with ten pieces left. There's less brilliance going on than people think. Its about exploiting opportunities or mistakes.

The AI google uses just exploits opportunities its seen a million times over millions of games. Lee, making the occasional mistake against a computer opens it up for the computer winning since it always exploits those mistakes. That causes enough of a point differential to win.

I write game AIs and they are less interesting than people think. This is interesting as it hasn't been done before, but that's about it.

Evolutionary neural network have been done for years, this certainly isn't the first time. They even interviewed Fogel who's work on evolutionary checkers AI was a big deal, and requires very little programming at all. You let the computer play game against itself over and over until it evolves better play. With no work whatsoever he managed to make his checkers AI become rated at a master level.

That's why this is less impressive than people think it is. It's the same thing as a computer beating a human at chess, checkers, or TTT. Its the exact same processes except with much more computing power dedicated to it.