Opening strategies in the Game of Go from feudalism to superhuman AI

How does information infrastructure shape long-term cultural evolution? Using 424 years of professional game records from the game of Go, this study explores how strategic dynamics in opening moves reflect historical shifts in the ``infostructure'' of Go players. Drawing from recent work on the potential impacts of population size, artificial intelligence and information technology on cultural diversity and innovation dynamics, I analyze over 118,000 games using measures of cultural diversity, divergence, and player network composition. The results show distinct eras of collective innovation and homogenization, including an early 20th-century explosion of novel opening strategies, a Cold-War-era die-off, and a recent increase in evolutionary tempo with the arrival of the Internet and superhuman AI programs like AlphaGo. Player population size shows an inverse-U shape with respect to opening move diversity, and community detection algorithms indicate the recent decline in diversity accompanied by a shift from many small subgroups in the player network to a few large ones. Surprisingly, the influence of AI has produced only a modest, short-lived disruption in opening move diversity, suggesting human-AI convergence and incremental, rather than revolutionary, change.