SAL: A Game Learning Machine Joel Paulson & Brian Lanners

Introduction Why AI game playing? Why AI game playing? Why AI game learning? Why AI game learning? SAL (Michael Gherrity, 1993) SAL (Michael Gherrity, 1993) Search and Learning Search and Learning

Consistency Search Basic Concept Basic Concept Reasons for Use Reasons for Use  Allows for Errors in Evaluation Function  Pathological Games

Procedure Consistent Positions Consistent Positions  Evaluation of a position is equal to its minimax value Inconsistent Positions Inconsistent Positions  Identifying and Correcting Errors

General Example If B is inconsistent, then one of the evaluations of B, D, or E is incorrect If B is inconsistent, then one of the evaluations of B, D, or E is incorrect

Consistency Search in Play

Organization of SAL Game Independent Kernel Game Independent Kernel  Consistency Search Algorithm  Evaluation Functions Game Specific Move Generator Game Specific Move Generator  Incorporates rules of game  Three Subroutines: MoveGenerator, MakeMove, EndOfGame

Features Used as input for Neural Network Used as input for Neural Network Feature Discovery Problem Feature Discovery Problem Features in SAL Features in SAL

Neural Networks SAL uses features for Input SAL uses features for Input Weights altered following each game using Temporal Difference Learning Weights altered following each game using Temporal Difference Learning

Performance of SAL Tic-Tac-Toe Tic-Tac-Toe Connect Four Connect Four Chess Chess