But Sony soon realized that speed alone was not enough to make the GT Sophy a winner. The program outperformed all human drivers on an empty track, setting superhuman lap times on three different virtual tracks. However, when Sony tested the GT Sophy in a race against multiple human drivers, where intelligence is required as well as speed, the GT Sophy lost. The program was at times too aggressive, collecting fines for reckless driving, and sometimes too timid, giving way when it shouldn’t have.
Sony regrouped, retrained its AI and staged a rematch in October. This time GT Sophy won easily. What made the difference? It’s true that Sony is back with a bigger neural network, giving its program more drawing-on-the-fly capabilities. But in the end, the difference came down to giving GT Sophy something that Peter Wurman, head of Sony AI America, calls “etiquette”: the ability to balance its aggression and timidity, choosing the most appropriate behavior for a given situation.
This is also what makes GT Sophy relevant beyond Gran Turismo. Etiquette between drivers on a track is a specific example of the kind of dynamic, context-aware behavior expected of robots interacting with humans, Wurman says.
Knowing when to take risks and when to play it safe would be useful for artificial intelligence that is better at interacting with humans, whether on the production floor, in home robots or in driverless cars.
“I don’t think we’ve yet learned the general principles of how to deal with human norms that you have to respect,” says Wurman. “But it’s a start and hopefully it will give us insight into this problem in general.”
GT Sophy is just the latest in a series of AI systems that have beaten the world’s best players in a variety of games, from chess and Go to video games like Starcraft and DOTA. But Gran Turismo offered Sony a new kind of challenge. Unlike other games, especially turn-based ones, Gran Turismo challenges its best players to control a vehicle at the limits of what is physically possible, in real-time, and in close proximity to other players trying to do the same.