10 years ago when I was learning Go. I can beat the strongest bot within months of learning the rule. Super amateur human play in Go AI is barely 5 years ago, if that.
That doesn't affect my core point: many of the things that humans have commonly associated with intelligence have been the first to fall. In hindsight it makes sense, we mistakenly assumed that there was such a thing as a universal rank of difficulty centered on what humans find hard to reason about.
More to your point, my decades remark had a weaker notion of amateur. For each game, we've had something that could beat most humans for decades. But you're right, that's not a useful distinction.
If we look just at Go the decades remark is somewhat of a stretch. Go has been especially difficult, requiring more intelligent algorithms in order to solve branching and state evaluation (and the latter in particular, is a function too complex to fit in human consciousness).
But progress has been occurring for years. On 9x9 boards MCTS bots have been stronger than most humans since about 2007, 10 years ago. For 19x19 it's true, if we pick 4 or 5 dan as better than most amateurs then that's 6/7 years.
