What’s the history and timeline for AI applied to the 9x9 game?
About a couple of years before the AlphaGo breakthrough, I read an article talking about AI and board games. Since this was ~1-2 years B.A. (Before AlphaGo), the article said that 19x19 Go appeared to still be far out of the reach of machine domination. However, the article did also mention that AI had reached superhuman strength in the 9x9 game, but it did not go into any historical details about that, since it was just a passing comment alongside other comments that robots have reached superhuman in several other board games (like chess, checkers, backgammon, etc.).
I was just wondering when we actually reached the point of superhuman AI for 9x9. Was this also fairly recent or did it occur much longer ago? It seems that milestone was much less publicized than the 19x19 accomplishment.
EDIT: I found the article that I was remembering (or rather slightly misremembering):
https://spectrum.ieee.org/robotics/artificial-intelligence/ais-have-mastered-chess-will-go-be-next
Turns out it actually says (in June 2014):
On the 9-by-9 board, top programs are on a par with the best human players.
However, it leaves ambiguous when this milestone was reached, and doesn’t mention any other historical details.
EDIT: for anyone that stumbles across this, my question was thoroughly answered by @Deep_Scholar and @mark5000 in another thread: