Last year, after Google's AlphaGo dispatched a human grandmaster in the notoriously complex board game for the first time, 19-year-old Ke Jie expressed confidence he wouldn't share the same fate, according to The New York Times. After all, Ke had defeated Lee Sedol several times before himself.

By the match's end Tuesday, Ke felt markedly different about his inhuman competitor.

"Last year, it was still quite humanlike when it played," Ke said. "But this year, it became like a god of Go."