Independent research lab OpenAI designed virtual agents to play hide-and-seek. They evolved increasingly clever strategies, eventually hacking the game world’s physics to gain advantage.

Deep reinforcement learning has given machines apparent hegemony in vintage Atari games, but their scores have been hard to compare — with one another or with human performance — because there are no rules governing what machines can and can’t do to win. Researchers aim to change that.

Theoretical advances can be thrilling, but the excitement can drown out all the ways AI is actually being put to use. DeepIndex provides an up-to-date, well organized, cheeky guide to practical applications culled from news reports.

Researchers typically test deep reinforcement learning algorithms on games from Space Invaders to StarCraft. The Google Brain team in Zurich adds another option: football, also known as soccer.

Alphabet subsidiary DeepMind lost $572 million in the past year, and its losses over the last three years amounted to more than $1 billion. AI contrarian Gary Marcus used the news as an opportunity to question the direction of AI as an industry.