AI is rewiring how the world’s best Go players think
The AI Revolution in Go: How Technology is Rewiring the World's Best Players
Burrowed in the alleys of Hongik-dong, a hushed residential neighborhood in eastern Seoul, is a faded stone-tiled building stamped "Korea Baduk Association," the governing body for professional Go. The game is an ancient one, with sacred stature in South Korea. But inside the building, rooms once filled with the soft clatter of hands dipping into wooden bowls of stones now echo with mouse clicks. Players hunch over their monitors and replay their matches in an AI program. Others huddle around a Go board and debate the best next move, while coaches report how their choices stack up against the AI's. Some sit in silence, watching AI programs play against each other.
Ten years ago, AlphaGo, Google DeepMind's AI program, stunned the world by defeating the South Korean Go player Lee Sedol. And in the years since, AI has upended the game. It's overturned centuries-old principles about the best moves and introduced entirely new ones. Players now train to replicate AI's moves as closely as they can rather than inventing their own, even when the machine's thinking remains mysterious to them. Today, it is essentially impossible to compete professionally without using AI. Some say the technology has drained the game of its creativity, while others think there is still room for human invention.
The Rise of AI in Go
To train AI to play Go, a vast trove of human Go moves are fed into a neural network, a computing system that mimics the web of neurons in the human brain. AlphaGo, which was later christened AlphaGo Lee after its victory over Lee Sedol, was trained on 30 million Go moves and refined by playing millions of games against itself. In 2017, its successor, AlphaGo Zero, picked up Go from scratch. Without studying any human games, it learned by playing against itself, with moves based only on the rules of the game. The blank-slate approach proved more powerful, unconstrained by the limits of human knowledge. After three days of training, it beat AlphaGo Lee 100 games to zero.
Google DeepMind retired AlphaGo that same year. But then a wave of open-source models inspired by AlphaGo Zero emerged. Today, KataGo is the program most widely used by professional Go players in South Korea. It's faster and sharper than AlphaGo. It's learned to predict not just who will win, but also who owns each point on the board at any given moment. While AlphaGo Zero pieced together its understanding of the board by looking at small sections, KataGo learned to read the whole board, developing better judgment for long-term strategies. Instead of just learning how to win, it learned to maximize its score.
The Impact on Players
The software has reshaped how people play. For hundreds of years, professional Go players have navigated the game's astronomical complexity by developing heuristics that replaced brute calculation. Elegant opening strategies imposed abstract order on the empty grid. Invading corners early was a bad bargain. Each generation of Go players added new principles to the canon. But "AI has changed everything," says Park Jeong-sang, a South Korean Go commentator. "Fundamental moves that were once considered common sense aren't played at all today, and techniques that didn't exist before have become popular."
The starkest shift has been in opening moves. Go starts on a blank grid, and the first 50 moves were canvases for abstract thinking and creativity, where players etched their personalities and philosophies. Lee Sedol fashioned provocative moves that invited chaos. Ke Jie, a Chinese player who was defeated by AlphaGo Master in 2017, dazzled with agile, imaginative moves. Now, players memorize the same strain of efficient, calculated opening moves suggested by AI. The crux of the game has shifted to the middle moves, where raw calculation matters more than creativity.
The Democratization of Go
Training with AI has led to a homogenization of playing styles. Ke Jie has lamented the strain of watching the same opening moves recycled endlessly. "I feel the exact same way as the fans watching. It's very tiring and painful to watch," he told a Chinese news outlet in 2021. Fans revel when a player breaks from the script with offbeat moves, but those moments have become rarer. Over a third of moves by the top Go players replicate AI's recommendations, according to a study in 2023. The first 50 moves of each game are often identical to what AI suggests, many players say.
The Future of Go
Researchers are trying to discover the superhuman knowledge encoded in game-playing AI programs so that humans can learn it too. In 2024, researchers at Google DeepMind extracted new chess concepts from AlphaZero, a generalized version of AlphaGo Zero that can also play chess, and taught them to chess grandmasters using chess puzzles. The Go concepts that players have picked up from AI systems so far are "probably only a small portion of what you could potentially learn," says Nicholas Tomlin, a computer scientist at Toyota Technological Institute at Chicago, who coauthored a study probing Go concepts encoded in AlphaGo Zero.
But extracting those lessons remains a struggle. "Top-tier players haven't yet been able to deduce the general principles behind AI moves," says Nam Chi-hyung, a Go professor at Myongji University. Although they can emulate AI's moves, they have yet to glean a new paradigm for the game because its reasoning is a black box, she says. Go may be in an epistemic limbo.
The Silver Lining
Even if AI is an opaque teacher, it's a democratic one. It has supercharged training for female Go players, who have long been underdogs of the game. For decades, training meant studying under top male players, and the most competitive matches took place in male circles that were difficult for women to break into, says Nam. "Female players never had access to that experience," she says. "But now they can study with AI, which has made their training environment much more favorable." More broadly, AI has narrowed the gap between players by helping everyone perfect their opening moves.
Conclusion
The AI revolution in Go has brought about a new era of competition and innovation. While some may lament the loss of creativity and human touch, others see the potential for AI to unlock new levels of understanding and achievement. As the game continues to evolve, one thing is certain: the future of Go will be shaped by the intersection of human ingenuity and artificial intelligence.
