Loading presentation...

Present Remotely

Send the link below via email or IM


Present to your audience

Start remote presentation

  • Invited audience members will follow you as you navigate and present
  • People invited to a presentation do not need a Prezi account
  • This link expires 10 minutes after you close the presentation
  • A maximum of 30 users can follow your presentation
  • Learn more about this feature in our knowledge base article

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.


The Game of Go

An introduction to the game of go, with history, rules, culture and computer go research

Herman Hiddema

on 29 March 2014

Comments (0)

Please log in to add your comment.

Report abuse

Transcript of The Game of Go

- History
- Rules of the Game
- The Modern Game
- Research
- Questions
- Try it out
The Game of Go
before 500 BC
Korea & Japan
5th-7th century
an Introduction
How to Play
start with an empty board
black and white take turns
put stones on intersections

the goal, simply put, is to put as many stones on the board as you can
Standard size board: 19x19
Any size works
13x13 and 9x9 are also popular
surround to capture
stones have liberties
take the last liberty to capture
Orthogonally adjacent is connected
Connected stones form chains
Chains share liberties
Chains are also captured by surrounding
Chains & Liberties
Capturing yourself is not allowed
Except if you capture stones
In which case you create your own liberties
Suicide & Capture
With the rules we have covered so far,
we can play "capture go"
Interlude: Capture Go
Try it online:
You are not allowed to repeat a position
This is called the Ko rule
Ko (repetition)
You can "pass", foregoing your turn
If both players pass, the game is over
You score:
the stones you have on the board
the empty points you've surrounded
End of a Game
The Rules
Kyu: student ranks
Dan: master ranks
Professional ranks
From 30 kyu (weakest)
To 1 kyu (strongest)
From 1 dan (weakest)
To 7 dan (strongest)
Professional master ranks:
1 dan - 9 dan
Top players are called "professionals"
China, Japan and Korea dominate
Fewer than 10 Western Professional Players
Top Players
an enduring challenge
Computer Go
What makes Go so hard for a computer?
Large branching factor creates a huge game tree
Lack of simple evaluation functions
Subtle long term effects of strategic choices
Pattern recognition
Influence maps
Expert systems
Neural networks
Early Approaches
Monte-Carlo Tree Search (MCTS)
The Breakthrough
Focuses on what the computer excels at: Doing many simple calculations really fast
Works well for long term effects, because it plays games out until the end
Subtle advantages are more likely to show over many simulations
The go "landscape" is relatively smooth
Add a node to the tree
Play many (random) playouts from here
Update winning percentages of parents
Why does it work?
Go in the Rest of the World
Reached the West only around 1900 AD
Currently played in some 70 countries
First professional initiatives now springing up
Result: Failure
Programs rarely achieved better than 10 kyu
Most programs had reproducible weaknesses
Programs did not scale or parallelize easily
Result: Success!
On 9x9, programs play on par with professionals
On 19x19, strong amateur level is reached (around 5 dan)
Current Research
Improved playout algorithms
Feedback from playouts
Patch specific weaknesses
Application to other fields
Handicap System
Black gets one extra free move at the start of the game for each rank difference

Works suprisingly well at all levels, and scales too.
a lot of catching up to do
Full transcript