1. 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

2. 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

3. 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

4. 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

5. 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

6. 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

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

8. 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

9. 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.

10. 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”

11. 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

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