Tonight during Valve’s yearly Dota 2 tournament, a surprise segment introduced what could be the best new player in the world -- a bot from Elon Musk-backed startup OpenAI. Engineers from the nonprofit say the bot learned enough to beat Dota 2 pros in just two weeks of real-time learning, though in that training period they say it amassed “lifetimes” of experience, likely using a neural network judging by the company’s prior efforts . Musk is hailing the achievement as the first time artificial