Wei Qi, Baduk, Go a game of strategy China Korea Japan & others Wei Qi, Baduk, Go a game of strategy Fred Hansen The Official Fred Spring 05

Why play go? Fun Challenge Think differently A window to the orient not procedural A window to the orient Only one rule Warning: It takes time to “get” go

What does go look like? Board with 19 x 19 lines White and black stones in bowls On your turn, put a stone on an intersection

What is the goal? Get the most stones on the board The game ends when surround bigger empty space keep groups alive The game ends when neither player wants to play there’s no more space to grab In practice not all intersections are filled when it is clear what color goes there

How a game might begin Players take turns putting stones black’s potential territory – 29 points white’s potential territory – 38 points White is ahead

How a game might end Neither player can gain points White wins Cannot be part of an immortal group; effectively dead black’s territory – 35 points white’s territory – 46 points White wins

Could black do better? Second move too “low” Better to be higher; push white lower

How does a stone die? A “liberty” is an empty intersection adjacent along a line A stone without liberties is dead It is removed from the board No liberties  dead

So, what is a liberty? A stone’s total liberties are its own, plus Liberties for the black stones 3 2 those of adjacent same-color stones 4 3 2 3 2 1 6 Empty intersections count only once When it is played, a stone’s own liberties are checked after making any captures.

One Rule: No repeat The board pattern must not repeat A move is illegal if it leaves a board identical to what it was ever before Hence: cannot recapture simple “ko” If white captures, sometimes black makes a threat, white responds, & black recaptures black cannot recapture on the next turn a “ko threat”

Immortality A group with two holes is immortal Black could capture only by playing in both holes. The possibility of two holes is enough If black plays b, white plays a, and vice versa a b

“First capture” Goal – understand capture rules Method – play first capture First player to capture a stone wins 7 x 7 board makes it faster