需要一些关于如何实现评估功能的想法

Question

我正在开发一个国际象棋游戏，现在尝试实现一个极小极大算法，该算法使用一个棋子方表和棋子值来计算分数。我已经能够创建以下显示的方法，但不知道如何在 CalculateScore() 和 evaluatePieceScore() 方法中计算计件分数。拜托，我真的很困惑，需要帮助。

1) getPieceValue() 该方法返回分配给每个棋子的常量值 2) getScoreForPiecePosition() 获取指定位置的评价奖励 3) CalculateScore() 使用棋盘表计算并返回分数。 4) evaluatePieceScore() 根据轮到谁，将CalculateScore() 计算出的分数加到原始分数上。

public class MinimaxPlayer implements IPlayerHandler, EvaluationAlgorithm{

private Game chessgame;
private MoveChecker checker;
private BoardGUI boardgui;

private static int maxDepth = 2;

public MinimaxPlayer(Game chessgame){
    this.chessgame = chessgame;
    this.checker = chessgame.getMoveChecker();
    this.boardgui = new BoardGUI(chessgame);
}

@Override
public int getPieceValue(int type) {
    switch(type){
    case Piece.TYPE_PAWN: return 100;
    case Piece.TYPE_KNIGHT: return 320;
    case Piece.TYPE_BISHOP: return 325;
    case Piece.TYPE_ROOK: return 500;
    case Piece.TYPE_QUEEN: return 975;
    case Piece.TYPE_KING: return 32767;
    default: throw new IllegalArgumentException("Unknown piece type: "+ type);
    }
}



@Override
public int evaluatePieceScore() {
    int scoreBrown = 0;
    int scoreYellow = 0;
    for (Piece piece : this.chessgame.getPieces()) {
        if(piece.getColor() == Piece.BROWN_COLOR){
            scoreBrown +=
                getScoreForPieceType(piece.getType());
            scoreBrown +=
                getScoreForPiecePosition(piece.getRow(),piece.getColumn());
        }else if( piece.getColor() == Piece.YELLOW_COLOR){
            scoreYellow +=
                getScoreForPieceType(piece.getType());
            scoreYellow +=
                getScoreForPiecePosition(piece.getRow(),piece.getColumn());
        }else{
            throw new IllegalStateException(
                    "unknown piece color found: "+piece.getColor());
        }
    }

    // return evaluation result depending on who's turn it is
    int gameState = this.chessgame.getGameState();

    if( gameState == Game.GAME_STATE_BROWN){
        return scoreBrwon - scoreYellow;

    }else if(gameState == Game.GAME_STATE_YELLOW){
        return scoreYellow - scoreBrown;

    }else if(gameState == Game.GAME_STATE_END_YELLOW_WON
            || gameState == Game.GAME_STATE_END_BROWN_WON){
        return Integer.MIN_VALUE + 1;

    }else{
        throw new IllegalStateException("unknown game state: "+gameState);
    }
}

public int CalculateScore(int index, int pieceValue, int[] SquareTable ){
    int score = pieceValue;

    for(int i = 0; i < SquareTable.length; i++){
        score += getPieceValue(index.get(SquareTable[i]));

    }

    return 0;
}

@Override
public int getScoreForPiecePosition(int row, int column) {
    byte[][] positionWeight =
    { {1,1,1,1,1,1,1,1}
     ,{2,2,2,2,2,2,2,2}
     ,{2,2,3,3,3,3,2,2}
     ,{2,2,3,4,4,3,2,2}
     ,{2,2,3,4,4,3,2,2}
     ,{2,2,3,3,3,3,2,2}
     ,{2,2,2,2,2,2,2,2}
     ,{1,1,1,1,1,1,1,1}
     };
    return positionWeight[row][column];
}



private static int[] PawnSquareTable = new int[]
{
    0,  0,  0,  0,  0,  0,  0,  0,
    50, 50, 50, 50, 50, 50, 50, 50,
    10, 10, 20, 30, 30, 20, 10, 10,
     5,  5, 10, 25, 25, 10,  5,  5,
     0,  0,  0, 20, 20,  0,  0,  0,
     5, -5,-10,  0,  0,-10, -5,  5,
     5, 10, 10,-20,-20, 10, 10,  5,
     0,  0,  0,  0,  0,  0,  0,  0
};


private static int[] KnightSquareTable = new int[]
{
    -50,-40,-30,-30,-30,-30,-40,-50,
    -40,-20,  0,  0,  0,  0,-20,-40,
    -30,  0, 10, 15, 15, 10,  0,-30,
    -30,  5, 15, 20, 20, 15,  5,-30,
    -30,  0, 15, 20, 20, 15,  0,-30,
    -30,  5, 10, 15, 15, 10,  5,-30,
    -40,-20,  0,  5,  5,  0,-20,-40,
    -50,-40,-30,-30,-30,-30,-40,-50,
};


private static int[] BishopSquareTable = new int[]
{
    -20,-10,-10,-10,-10,-10,-10,-20,
    -10,  0,  0,  0,  0,  0,  0,-10,
    -10,  0,  5, 10, 10,  5,  0,-10,
    -10,  5,  5, 10, 10,  5,  5,-10,
    -10,  0, 10, 10, 10, 10,  0,-10,
    -10, 10, 10, 10, 10, 10, 10,-10,
    -10,  5,  0,  0,  0,  0,  5,-10,
    -20,-10,-10,-10,-10,-10,-10,-20,
};

    private static int[] RookSquareTable = new int[]
{
    0,  0,  0,  0,  0,  0,  0,  0,
    5, 10, 10, 10, 10, 10, 10,  5,
   -5,  0,  0,  0,  0,  0,  0, -5,
   -5,  0,  0,  0,  0,  0,  0, -5,
   -5,  0,  0,  0,  0,  0,  0, -5,
   -5,  0,  0,  0,  0,  0,  0, -5,
   -5,  0,  0,  0,  0,  0,  0, -5,
    0,  0,  0,  5,  5,  0,  0,  0,
};

    private static int[] QueenSquareTable = new int[]
{
    -20,-10,-10, -5, -5,-10,-10,-20,
    -10,  0,  0,  0,  0,  0,  0,-10,
    -10,  0,  5,  5,  5,  5,  0,-10,
     -5,  0,  5,  5,  5,  5,  0, -5,
      0,  0,  5,  5,  5,  5,  0, -5,
    -10,  5,  5,  5,  5,  5,  0,-10,
    -10,  0,  5,  0,  0,  0,  0,-10,
    -20,-10,-10, -5, -5,-10,-10,-20,
};


private static int[] KingMiddleGameSquareTable = new int[]
{
    -30,-40,-40,-50,-50,-40,-40,-30,
    -30,-40,-40,-50,-50,-40,-40,-30,
    -30,-40,-40,-50,-50,-40,-40,-30,
    -30,-40,-40,-50,-50,-40,-40,-30,
    -20,-30,-30,-40,-40,-30,-30,-20,
    -10,-20,-20,-20,-20,-20,-20,-10,
     20, 20,  0,  0,  0,  0, 20, 20,
     20, 30, 10,  0,  0, 10, 30, 20,
};


private static int[] KingEndGameSquareTable = new int[]
{
    -50,-40,-30,-20,-20,-30,-40,-50,
    -30,-20,-10,  0,  0,-10,-20,-30,
    -30,-10, 20, 30, 30, 20,-10,-30,
    -30,-10, 30, 40, 40, 30,-10,-30,
    -30,-10, 30, 40, 40, 30,-10,-30,
    -30,-10, 20, 30, 30, 20,-10,-30,
    -30,-30,  0,  0,  0,  0,-30,-30,
    -50,-30,-30,-30,-30,-30,-30,-50,
};


public static int[] reverse(int[] arr){
    ArrayUtils.reverse(arr);
    return arr;
}

}

Answer 1

如果您感到困惑，我建议您从一个简单的评估函数开始，仅考虑棋子的价值（棋子 1 分，主教和马 3 分，车 5 分，9 分女王和国王的很多积分，比如说200）

然后你的函数变成：

    public int calculateScore()
    {
        return blackPlayer.getMaterial() - whitePlayer.getMaterial()
    }

getMaterial() 函数将是您所有棋子点数的总和。

示例：黑方有 1 兵、1 后和 1 王，则 blackPlayer.getMaterial() 将返回 = 1 + 9 + 200 = 210

如果你想在评估函数中考虑到棋子的位置，你可以这样做：

    public int calculateScore()
    {
        int blackScore = blackPlayer.getMaterial() + blackPlayer.getBonusPosition();
        int whiteScore = whitePlayer.getMaterial() + whitePlayer.getBonusPosition();
        return blackScore - whiteScore; 
    }

getBonusPosition() 函数将返回您所有棋子的所有奖金位置得分的总和：

示例：blackPlayer 在 (0,0) 位置有 1 个棋子，在 (0,1) 位置有 1 个后，在 (2,2) 位置有一个国王：

• 棋子在 (0,0) 的奖励位置是 0
• 女王在 (0,1) 的奖金位置是 -10
• 国王（在最后阶段）在 (2,2) 的奖励位置是 -20

blackPlayer.getBonusPosition() 将返回 = 0 - 10 -20 = -30

您可以更改系数，以更加重视材料价值或在棋盘上的位置。例如，在前面的示例中，位置分数与材料分数相比太重要了。

示例：您想更加重视（假设是 10 倍）材料价值，并且您并不真正关心棋子在棋盘上的位置，然后您重新计算分数函数将是：

    public int calculateScore()
    {
        int blackScore = 10*blackPlayer.getMaterial() + blackPlayer.getBonusPosition();
        int whiteScore = 10*whitePlayer.getMaterial() + whitePlayer.getBonusPosition();
        return blackScore - whiteScore; 
    }

Answer 2

您缺少的部分是一个以 type、row 和 column 作为参数的函数：

public int getScoreForPieceTypeAndPosition(int type, int row, int
 column) { public int getPieceValue(int type) {
     switch(type){
     case Piece.TYPE_PAWN: return PawnSquareTable[row * 8 + column ];
     case Piece.TYPE_KNIGHT: return KnightSquareTable[row * 8 + column ];
     case Piece.TYPE_BISHOP: return BishopSquareTable[row * 8 + column ];
     case Piece.TYPE_ROOK: return RookSquareTable[row * 8 + column ];
     case Piece.TYPE_QUEEN: return QueendSquareTable[row * 8 + column ]; 
     case Piece.TYPE_KING: return KingSquareTable[row *8 + column];
     default: throw new IllegalArgumentException("Unknown piece type: "+ type);
     } }

并在整体计算中使用该方法。

[未测试]

对于像 Pawn 这样非对称的表可能还不够，那么您需要提供 BROWN 或 WHITE 参数并使用 ( 7 - row ) 调用函数，而不是 BROWN 的 row 示例。

（谷歌搜索 = http://chessprogramming.wikispaces.com/Simplified+evaluation+function）