The game of Go is much loved by geeks for its simplicity and subtlety. So it’s a little tragic to see AlphaGo, an AI developed by the alpha geeks at Google DeepMind, go 2-0 up against one of the best Go players in human history, Lee Se-dol.

The second game in the best-of-5 match not only demonstrated the program’s extraordinary strength as a Go player but also highlighted its ability to produce some surprisingly creative moves. These moves reflect the remarkable progress AI is making, as well as the gaps that still remain.

AlphaGo’s match against Se-dol is reminiscent of the battle between IBM’s Deep Blue and Garry Kasparov, then the world chess champion, in 1997. But Go is far more challenging for computers than chess, for two reasons: the number of potential moves in each turn is far higher, and there is no simple way to measure material advantage.