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Generation of Patterns with External Conditions for the

Game of Go

Paper presentation

http://www.ai.univ-paris8.fr/~cazenave/acg9.pdf

Author: Tristan Cazenave

Presentation by: Adi Botea

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Outline

Motivation Go Patterns with External Conditions

– What they are– Representation– Generation

Experimental Results Conclusion

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Motivation

Heuristic Search needs enhancements (e.g., transposition tables)

Go Patterns can be a powerful enhancement to Heuristic Search

Humans can learn from such databases

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Go Patterns with External Conditions

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Go Patterns with External Conditions

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Go Patterns with External Conditions

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Go Patterns with External Conditions External Conditions:

– It is the number of external liberties of groups that matters

– Used in many Go programs BUT…– Now they are generated automatically

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Go Patterns with External Conditions

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Representation

MaxNrLibertyIfEnemy: no conditions, 0, 1 MinNrLibertyIfFriend:no conditions, 1, 2 MaxNrLiberty:no conditions, 0, 1 MinNrLiberty:no conditions, 1, 2

9x9x3x3 = 729 rules

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RepresentationMoves for White:

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Included Patterns

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Included Patterns

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Number of Possible Patterns

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Generation

Each pattern coded as a 32-bit integer Save memory:

– Only a few rules lead to win or winning positions

– Different sets of conditions can be associated with a pattern

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Generation

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Generation

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Generation

Further optimizations:– Unmove only the last deduced patterns– Order of Test and Cut– Rule-Coverage Reductions

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Results – Eyes on the side

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Results – Life in the Corner

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Results

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Results

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Results

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Conclusion

Go Patterns with External Conditions:– What are they?– How to represent them?– How to generate them?– Results