Go has been studied for hundreds of years. In many cases, by people who study the game since their childhood and work on it as a full-time occupation. The cons

Go has been studied for hundreds of years. In many cases, by people who study the game since their childhood and work on it as a full-time occupation. The consequence of Alpha Go Zero is that it can, in a matter of days, disregard and surpass all human knowledge about the game. Maximizing a score margin has been equated for a long time with maximizing your probability of winning. Alpha Go doesn't play like that... it's a substantial paradigm shift. If you see the early commentaries you will see that human players were initially saying Alpha Go moves were mistakes because they were slow and wasted opportunities to get more territory, to then realize that Alpha Go was actually winning.