AlphaGo’s Decision Making Woosuk Park School of Humanities and Social Sciences, KAIST e_wspark@kaist.ac.kr Sungyong Kim Graduate School of Culture Technology, KAIST simonksy@kaist.ac.kr Keunhyoung Luke Kim Graduate School of Culture Technology, KAIST dilu@kaist.ac.kr Jeounghoon Kim ∗ School of Humanities and Social Sciences, Graduate School of Culture Technology, KAIST miru@kaist.ac.kr Abstract In this paper, we study the similarities and differences between the process of decision making in humans and AlphaGo in playing Baduk (Go, Weiqi). Pre- vious discussions of unique or unconventional moves of AlphaGo ignored how AlphaGo tends to play in different situations: (1) when AlphaGo is leading the game, (2) when she is falling behind, and (3) when the situation of the game is close enough. Nor did they pay due attention to the problem of strategic choice of moves of AlphaGo. We argue that (1) that AlphaGo tends to play very thick and safe enclosing moves when she is leading the game, (2) that she tends to play do-or-die (all-or-nothing or gambling) moves that are backed up by very carefully calculated scheming strategy, when there is no hope to win the game, and (3) that she tends to figure out creative moves in order to take the initiative, when the game is close enough. After sharpening the concept of * corresponding author at KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea. We are grateful to the anonymous reviewers whose detailed comments and wonderful suggestions helped greatly improve the manuscript. Vol. 6 No. 1 2019 Journal of Applied Logics — IFCoLog Journal of Logics and their Applications