Popular openings amongst amateur online Go players: insights from data-informed analysis

Quentin Rendu et al. /June 27, 2026

Abstract
Starting from an empty board,the number of legal positions in a Go game grows exponentially as the number of moves increase.During the early moves,a very large subset of the possible positions have balanced win rates. This suggests that the choice of the opening is not crucial to decide a Go game.Nevertheless it is important for players to know what kind of openings they will most frequently face.To answer this question,we collected half a million games played on Fox Go server from 2013 to 2019 amongst players ranked between 10 kyu and 9 dan.A data-informed methodology was developed to classify and compute the frequency of the different openings before and after the introduction of AI.The most popular first moves are nirensei and hoshi+34 .Deeper openings popularity depends on rank.Sanrensei frequency decreases with rank,Chinese opening is most popular below 5 dan and Kobayashi between 3 dan and 7 dan (Fox Go Server ranks).The results also show a change in opening playstyle for players ranked above 4 dan after the rise of Go AI.Up to 2019,a similar change is not observed amongst lower ranked players.


Keywords: Go opening,Data-informed,Fox Go dataset