Este es un ajedrez-KOTH con reglas simplificadas (porque el ajedrez en sí mismo ya es complicado, jugarlo a través de un programa simple no lo hace más fácil). Por el momento está limitado a Java (versión 8), pero crear una clase de envoltura no es tan difícil (en caso de que alguien quiera hacer esto).

Tablero de ajedrez

El tablero de ajedrez en el programa de control usa una versión modificada de la notación numérica ICCF . Está basado en cero, lo que significa que el campo inferior izquierdo es la posición 0,0, mientras que el campo superior derecho es la posición 7,7.

Reglas modificadas

• En passant será ignorado.
• El enroque no es posible.
• La regla de los cincuenta movimientos se aplica automáticamente (lo que significa que el juego termina en empate).
• La promoción de peones a reinas se realiza automáticamente cuando llegan al final del tablero.
• Si un jugador necesita más de 2 segundos para moverse, perderá el juego.
• Devolver un movimiento no válido dará como resultado la pérdida del juego.
• Para ganar, tienes que capturar al rey enemigo . No es suficiente jaquetear al enemigo.
• Esto también te permite mover a tu rey a campos donde el enemigo puede capturarte.
• Las blancas comienzan el juego.
• El blanco se coloca "en la parte inferior" del campo (y = 0), el negro se encuentra en la parte superior (y = 7).
• Está prohibido acceder a otros recursos que no sean su bot (internet, archivos, otros bots, ...).

Tanteo

• Ganar te otorga 3 puntos, un empate de 1 punto y perder 0 puntos.
• Cada presentación jugará una contra la otra 10 veces (5 veces como blanco, 5 como negro).

Controlador

Puede encontrar el programa de control en github .
Para participar, debe crear una clase dentro delplayerpaquete y debe ser una subclase dePlayer. Como ejemplo, mira TestPlayer (que también se incluirá en la puntuación).

Cada juego, el controlador creará una nueva instancia de tu jugador. Luego, cada turno tienes que devolver un movimiento. El controlador le proporciona una copia de la placa , que contiene una matriz de campos de 8x8 . Un campo contiene información sobre su color, su posición y la pieza que contiene , si hay uno.
El controlador también te proporciona información sobre el jugador enemigo, como isChecky getPieces(). Llamar getMove()al enemigo te descalificará.

Marcador

01) AlphaBetaPV: 229
02) AlphaBeta: 218
03) PieceTaker: 173
04) Queso: 115
05) ThreeMoveMonte: 114
06) StretchPlayer: 93
07) No pienses adelante: 81
08) SimplePlayer: 27
09) TestPlayer: 13

El concurso se limita a Java porque facilita la creación de respuestas, ya que puede beneficiarse de los métodos proporcionados por el controlador. Sin embargo, si alguien crea un contenedor, incluiré otros idiomas.

AlphaBetaPV

AlphaBetaPV significa Alpha Beta con variación principal (no es una búsqueda de variación principal). Con solo unas pocas líneas más entrelazadas en el código de AlphaBeta.java, supera a AlphaBeta.java. Y de nuevo, lo siento, por solo transformar y fusionar códigos de otras fuentes de Internet en este código JAVA.

• La variación principal se almacena y se usa para la prioridad de movimiento más simple para acelerar el corte alfa beta:
  • mientras que la profundización iterativa y
  • para el próximo movimiento
• Evaluación de posición simple:
  • Número de movimientos que tiene cada parte (grado de libertad) para apoyar la apertura.
  • Promoción de peones para apoyar el juego final.
• Todavía no hay búsqueda de reposo.

Sigue jugando aburrido.

package player;

import java.util.Random;
import controller.*;

public class AlphaBetaPV extends Player {
    private static final int INFINITY = Integer.MAX_VALUE;
    private static final int MAXTIME = 1800; // max time for evaluation
    private static final Random random=new Random();
    private static int seed=1;

    private long time; // time taken this turn
    private int iterativeDepth;
    private Player myOpponent;
    private int commitedDepth;

    private static Piece[] pieces = new Piece[20000];
    private static Point[] points = new Point[20000];
    private static int[] freedom = new int[20];

    private static class PV {
        Move move;
        PV next;
    }       
    private PV pv= new PV();

    @Override
    public Move getMove(Board root, Player min) {
        time=System.currentTimeMillis();
        seed++; myOpponent=min;
        // use last PV for an estimate of this move
        if (pv.next!=null) pv=pv.next;
        if (pv.next!=null) pv=pv.next;
        iterative_deepening(root);
        return pv.move;
    }

    private void iterative_deepening(Board root) {
        try {
            for (iterativeDepth = (commitedDepth=Math.max(2, commitedDepth-2));; iterativeDepth++) {
                alphaBeta(root, -INFINITY, +INFINITY, iterativeDepth, this, myOpponent, 0, 0, pv, pv);
                commitedDepth=iterativeDepth;
            }
        } catch (InterruptedException e) {}
    }

    //http://chessprogramming.wikispaces.com/Alpha-Beta
    private int alphaBeta(Board root, int alpha, int beta, int d, Player max, Player min, int begin, int level, PV pv, PV pline) throws InterruptedException {
        if (d==0 || root.getKing(max) == null) return evaluate(root, d, level);
        int end = allMoves(root, max, begin, level, pv);
        PV line= new PV();
        for (int m=begin; m<end; m++) {
            Board board = root.copy();
            board.movePiece(new Move(pieces[m].copy(), points[m]));
            int score = -alphaBeta(board, -beta, -alpha, d - 1, min, max, end, level+1, pline==null?null:pline.next, line);
            if (score >= beta)
                return beta; // fail hard beta-cutoff
            if (score > alpha) {
                pline.move=new Move(pieces[m].copy(), points[m]); // store as principal variation
                pline.next=line; line=new PV();
                alpha = score; // alpha acts like max in MiniMax
            }
        }
        return alpha;
    }

    private int evaluate(Board board, int d, int level) throws InterruptedException {
        if ((System.currentTimeMillis() - time) > MAXTIME)  throw new InterruptedException();
        int minmax=2*((iterativeDepth-d)&1)-1;
        int king = 0, value=(level>1)?minmax*(freedom[level-1]-freedom[level-2]):0;
        Field[][] field = board.getFields();
        for (int x = 0; x < 8; x++) {
            for (int y = 0; y < 8; y++) {
                Piece piece = field[x][y].getPiece();
                if (piece==null) continue;

                int sign=(piece.getTeam()==getTeam())?-minmax:minmax;
                switch (piece.getType()) {
                case PAWN:      value += (  1000+2*(piece.getTeam()==Color.WHITE?y:7-y))*sign; break;
                case KNIGHT:    value +=    3000*sign; break;
                case BISHOP:    value +=    3000*sign; break;
                case ROOK:      value +=    5000*sign; break;
                case QUEEN:     value +=    9000*sign; break;
                case KING:      king  += (100000-(iterativeDepth-d))*sign; break;
                default: // value += 0;
                }
            }
        }
        return king==0?value:king;
    }

    private int allMoves(Board board, Player player, int begin, int level, PV pv) {
        random.setSeed(seed);
        int m=0;
        for (Piece piece : player.getPieces(board)) {
            for (Point point: piece.getValidDestinationSet(board)) {
                // shuffle and store
                int r=begin+random.nextInt(++m);
                points[begin+m-1]=points[r];    pieces[begin+m-1]=pieces[r];
                points[r]=point;                pieces[r]=piece;
            }
        }
        freedom[level]=m;
        if (pv!=null && pv.move!=null)  { // push PV to front
            for (int i = 0; i < m; i++) {
                if (pv.move.getPiece().equals(pieces[begin+i]) && pv.move.getDestination().equals(points[begin+i])) {
                    Point point = points[begin];    Piece piece = pieces[begin];
                    points[begin]=points[begin+i];  pieces[begin]=pieces[begin+i];
                    points[begin+i]=point;          pieces[begin+i]=piece;  
                    break;
                }
            }
        }
        return begin+m;
    }
}

PieceTaker

El código es un poco desordenado, pero funciona. En este momento gana contra todos los demás jugadores, incluso si solo recibe 400 ms en lugar de los 2000 ms permitidos.

Estoy usando la poda alfa beta con profundización iterativa para asegurarme de que la IA no supere el límite de tiempo. La heurística actual es muy simple (solo se toman en cuenta las piezas perdidas / tomadas; no la posición en el tablero, etc.).

En el futuro, también podría agregar heurísticas asesinas y ordenar los movimientos antes de examinarlos.

package player;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Random;

import controller.*;

public class PieceTaker extends Player {

    private boolean DEBUG = false;
    private Player pieceTaker;
    private static final int MAXINT = Integer.MAX_VALUE / 2;
    private static final int MININT = Integer.MIN_VALUE / 2;
    private static final boolean ITERATIVE_DEEPENING = true;
    private static final int MAX_DEPTH = 6; // max depth if not using iterative
                                            // deepening
    private static int MAXTIME = 400; // max time for evaluation (if using
                                        // iterativeDeepening). We still need to
                                        // evaluate moves, so save time for
                                        // that.
    private long time; // time taken this turn

    @Override
    public Move getMove(Board board, Player enemy) {
        pieceTaker = this;
        // generate all possible moves
        List<Move> possibleMoves = new ArrayList<>();
        List<Piece> pieces = this.getPieces(board);
        for (Piece piece : pieces) {
            Point[] destinations = piece.getValidDestinations(board);
            for (Point point : destinations) {
                possibleMoves.add(new Move(piece, point));
            }
        }

        // rate moves
        Move best = getNextMove(board, possibleMoves, enemy);
        return best;
    }

    private Move getNextMove(Board board, List<Move> possibleMoves, Player enemy) {
        time = System.currentTimeMillis();

        // wrap moves in node class and apply move
        List<Node> children = new ArrayList<>();
        for (Move move : possibleMoves) {
            Node newNode = new Node(move, board, this, enemy, 0);
            newNode.applyAndRateMove();
            children.add(newNode);
        }

        if (ITERATIVE_DEEPENING) {
            for (int depth = 1;; depth++) {
                List<Node> copy = new ArrayList<>();
                // copy nodes (so that in case time is over we still have a valid set)
                for (Node node : children) {
                    copy.add(node.copy());
                }
                // rate copy
                rateMoves(copy, depth);
                if ((System.currentTimeMillis() - time) > MAXTIME) {
                    break;
                }
                // copy rated nodes back
                children = new ArrayList<>();
                for (Node node : copy) {
                    children.add(node.copy());
                }
            }
        } else {
            rateMoves(children, MAX_DEPTH);
        }

        return getBestMove(children);
    }

    // returns node with the highest score
    private Move getBestMove(List<Node> nodes) {
        if (DEBUG) {
            System.out.println("\n");
            for (Node node : nodes) {
                System.out.println(node.toString());
            }
        }

        Collections.sort(nodes, new ComparatorNode());

        // get all nodes with top rating
        List<Node> best = new ArrayList<>();
        int bestValue = nodes.get(0).getRating();
        for (Node node : nodes) {
            if (node.getRating() == bestValue) {
                best.add(node);
            }
        }

        Random random = new Random();
        Node bestNode = best.get(random.nextInt(best.size()));
        if (DEBUG) {
            System.out.println("using: " + bestNode.toString());
        }
        return bestNode.getMove();
    }

    private void rateMoves(List<Node> nodes, int depth) {
        if (nodes.size() == 1) {
            // nothing to rate. one possible move, take it.
            return;
        }

        for (Node node : nodes) {
            int alphaBeta = alphaBeta(node, depth, MININT, MAXINT);
            node.setRating(alphaBeta);
        }
    }

    protected int alphaBeta(Node node, int depth, int alpha, int beta) {
        Player currentPlayer = node.getCurrentPlayer();
        Player otherPlayer = node.getOtherPlayer();
        // game over
        if (node.getBoard().getKing(currentPlayer) == null) {
            if (currentPlayer == this) {
                return node.getRating() - 999;
            } else {
                return node.getRating() + 999;
            }
        } else {
            // TODO check for draw and rate draw (might be good to take it)
        }
        if (depth <= 0) {
            return node.getRating(); // the rating in the move is always as seen
                                        // for player, not current player
        }

        List<Node> children = getPossibleMoves(node);
        if (otherPlayer == this) {
            for (Node child : children) {
                if ((System.currentTimeMillis() - time) > MAXTIME) {
                    break; // time over.
                }
                alpha = Math.max(alpha,
                        alphaBeta(child, depth - 1, alpha, beta));
                if (beta <= alpha) {
                    break; // cutoff
                }
            }
            return alpha;
        } else {
            for (Node child : children) {
                if ((System.currentTimeMillis() - time) > MAXTIME) {
                    break; // time over.
                }
                beta = Math.min(beta, alphaBeta(child, depth - 1, alpha, beta));
                if (beta <= alpha) {
                    break; // cutoff
                }
            }
            return beta;
        }
    }

    private List<Node> getPossibleMoves(Node node) {
        List<Node> possibleMoves = new ArrayList<>();
        List<Piece> pieces = node.getOtherPlayer().getPieces(node.getBoard());
        for (Piece piece : pieces) {
            Point[] destinations = piece.getValidDestinations(node.getBoard());
            for (Point point : destinations) {
                Node newNode = new Node(new Move(piece, point),
                        node.getBoard(), node.getOtherPlayer(),
                        node.getCurrentPlayer(), node.getRating());
                if (newNode.applyAndRateMove()) {
                    possibleMoves.clear();
                    possibleMoves.add(newNode);
                    return possibleMoves; // we won, return wining move
                }
                possibleMoves.add(newNode);
            }
        }
        return possibleMoves;
    }

    private class Node {
        private Move move;
        private Move originalMove;
        private Board board;
        private Player currentPlayer;
        private Player otherPlayer;
        private int rating;

        public Node(Move move, Board board, Player currentPlayer,
                Player otherPlayer, int rating) {
            super();
            this.move = new Move(move.getPiece().copy(), move.getDestination()
                    .copy());
            this.originalMove = new Move(move.getPiece().copy(), move
                    .getDestination().copy());
            // copy board so changes only affect this node
            this.board = board.copy();
            this.currentPlayer = currentPlayer;
            this.otherPlayer = otherPlayer;
            this.rating = rating;
        }

        @Override
        public String toString() {
            return " [" + originalMove.toString() + " (r: " + rating + ")] ";
        }

        public Node copy() {
            Node copy = new Node(new Move(originalMove.getPiece().copy(),
                    originalMove.getDestination().copy()), board.copy(),
                    currentPlayer, otherPlayer, rating);
            return copy;
        }

        public boolean applyAndRateMove() {
            // call rate before apply as it needs the unchanged board
            rateMove();
            board.movePiece(move);
            if (getBoard().getKing(currentPlayer) == null) {
                return true;
            } else {
                return false;
            }
        }

        private void rateMove() {
            Point dest = move.getDestination();
            Field destField = board.getFields()[dest.getX()][dest.getY()];

            int value = 0;
            if (destField.hasPiece()) {
                PieceType type = destField.getPiece().getType();
                switch (type) {
                case PAWN:
                    value = 1;
                    break;
                case KNIGHT:
                    value = 3;
                    break;
                case BISHOP:
                    value = 3;
                    break;
                case ROOK:
                    value = 5;
                    break;
                case QUEEN:
                    value = 9;
                    break;
                case KING:
                    value = 111;
                    break;
                default:
                    value = 0;
                }
            }

            if (currentPlayer == pieceTaker) {
                this.rating += value;
            } else {
                this.rating -= value;
            }
        }

        public Player getOtherPlayer() {
            return otherPlayer;
        }

        public Player getCurrentPlayer() {
            return currentPlayer;
        }

        public Board getBoard() {
            return board;
        }

        public int getRating() {
            return rating;
        }

        public void setRating(int r) {
            this.rating = r;
        }

        public Move getMove() {
            return originalMove;
        }
    }

    private class ComparatorNode implements Comparator<Node> {
        @Override
        public int compare(Node t, Node t1) {
            return t1.getRating() - t.getRating();
        }
    }
}

StretchPlayer

¡Este bot juega igual que yo!

Por cierto, soy terrible en el ajedrez.

Los comentarios explican lo que realmente está haciendo. Se parece mucho a mi proceso de pensamiento.

Como beneficio adicional, supera a todos los demás bots por un margen considerable. (hasta aquí)

EDITAR: ¡ahora predice al oponente ejecutándose como el enemigo!

EDITAR 2: El programa cometió el error de no matar al rey cuando estaba abierto. Fue reprendido en consecuencia.

import java.util.List;
import java.util.Set;

import controller.*;

public class StretchPlayer extends Player{

    boolean avoidStackOverflow = false;
    @Override
    public Move getMove(Board board, Player enemy) {
        List<Piece> pieces = this.getPieces(board);
        for(Piece piece:pieces){
            //first order of business: kill the enemy king if possible
            if(piece.getValidDestinationSet(board).contains(board.getKing(enemy).getPos())){
                return new Move(piece,board.getKing(enemy).getPos());
                }
        }
        //I suppose I should protect my king.
        for(Piece ePiece:enemy.getPieces(board)){
            if(ePiece.getValidDestinationSet(board).contains(board.getKing(this).getPos())){
                //ideally I would move my king.
                for(Point p:board.getKing(this).getValidDestinationSet(board)){
                    //but I don't want it to move into a spot where the enemy can get to. That would be suicide.
                    boolean moveHere=true;
                    for(Piece enemyPiece:enemy.getPieces(board)){
                        if(enemyPiece.getValidDestinationSet(board).contains(p)){
                            moveHere=false;
                        }
                    }
                    if(moveHere){
                        return new Move(board.getKing(this),p);
                    }
                }
                //so the king can't move. But I can fix this. There has to be a way!
                for(Piece myPiece:pieces){
                    for(Point possMove:myPiece.getValidDestinationSet(board)){
                        Board newBoard = board.copy();
                        newBoard.movePiece(new Move(myPiece,possMove));
                        if(!newBoard.isCheck(this, enemy)){
                            //Aha! found it!
                            return new Move(myPiece,possMove);
                        }
                    }

                }
                //uh-oh. Better just go with the flow. I'll lose anyway.
            }
        }
        for(Piece piece:pieces){
            Set<Point> moves = piece.getValidDestinationSet(board);
            for(Piece opponentPiece:enemy.getPieces(board)){
                if(moves.contains(opponentPiece.getPos())){
                    Point futurePosition = null;
                    //search for this illusive move (no indexOf(...)?)
                    for(Point p:moves){
                        if(p.getX()==opponentPiece.getPos().getX()&&p.getY()==opponentPiece.getPos().getY()){
                            futurePosition = p;
                        }
                    }
                    //it can now kill the enemies piece. But first, it should probably check if it is going to get killed if it moves there.
                    boolean safe = true;
                    for(Piece nextMoveOpponent:enemy.getPieces(board)){
                        if(nextMoveOpponent.getValidDestinationSet(board).contains(futurePosition)&&piece.getType()!=PieceType.PAWN){
                            safe = false;
                        }
                        //it would also be beneficial if the enemy didn't kill my king next round.
                        if(nextMoveOpponent.getValidDestinationSet(board).contains(board.getKing(this).getPos())){
                            safe = false;
                        }
                    }
                    if(safe){
                        return new Move(piece, futurePosition);
                    }

                }
            }
        }
        //ok, so I couldn't kill anything. I'll just put the enemy king in check!
        for(Piece piece:pieces){
            for(Point p:piece.getValidDestinationSet(board)){
                Piece simulatedMove = piece.copy();
                simulatedMove.setPos(p);
                if(simulatedMove.getValidDestinationSet(board).contains(board.getKing(enemy).getPos())){
                    return new Move(piece,p);
                }
            }
        }
        //hmmmm... What would I do if I was the enemy?
        if(!avoidStackOverflow){
            avoidStackOverflow = true;
            Board copy = board.copy();
            Move thinkingLikeTheEnemy = this.getMove(copy, this);
            avoidStackOverflow = false;
            Board newBoard = copy;
            //I wonder what piece it's targeting...
            Piece targeted =null;
            for(Piece p:pieces){
                if(p.getPos().getX()==thinkingLikeTheEnemy.getDestination().getX()&&p.getPos().getY()==thinkingLikeTheEnemy.getDestination().getY()){
                    targeted=p;
                }
            }
            //better move that piece out of the way, if it doesn't hurt my king
            if(targeted!=null){
                for(Point p:targeted.getValidDestinations(newBoard)){
                    newBoard = board.copy();
                    newBoard.movePiece(new Move(targeted,p));
                    for(Piece enemy2:enemy.getPieces(newBoard)){
                        if(!enemy2.getValidDestinationSet(newBoard).contains(p) && !newBoard.isCheck(this, enemy)){
                            return new Move(targeted,p);
                        }
                    }
                }
                newBoard.movePiece(new Move(targeted,thinkingLikeTheEnemy.getPiece().getPos()));
                if(!newBoard.isCheck(this, enemy)){
                    return new Move(targeted,thinkingLikeTheEnemy.getPiece().getPos());
                }
            }
        }

        //well, I guess this means I couldn't kill anything. Or put the enemy in check. And the enemy didn't have anything interesting to do
        //I guess I should just push a pawn or something
        for(Piece piece:pieces){
            if(piece.getType()==PieceType.PAWN){
                if(piece.getValidDestinationSet(board).size()>0){
                    return new Move(piece,piece.getValidDestinations(board)[0]);
                }
            }
        }
        //What!?!? No Pawns? guess I'll just move the first thing that comes to mind.
        for(Piece piece:pieces){
            if(piece.getValidDestinations(board).length>0){
                //providing that doesn't put my king in danger
                Board newBoard = board.copy();
                newBoard.movePiece(new Move(piece,piece.getValidDestinations(board)[0]));
                if(!newBoard.isCheck(this, enemy)){
                    return new Move(piece,piece.getValidDestinations(board)[0]);
                }
            }
        }
        //Oh no! I can make no moves that can save me from imminent death. Better hope for a miracle!
        for(Piece p:pieces){
            if(p.getValidDestinations(board).length>0){
                return new Move(p,p.getValidDestinations(board)[0]);
            }
        }
        //a miracle happened! (if it made it here)
        return null;
    }

}

Three Move Monte

Este tipo observa los siguientes tres movimientos (el mío, el tuyo, el mío) y elige el movimiento que otorga la puntuación más alta. Si hay más de 60 movimientos disponibles, solo elegirá 60 aleatorios en cada paso. Por supuesto, si cualquier movimiento individual (de todos ellos, no los 60 elegidos) terminará el juego, lo tomaré de inmediato.

Para anotar un tablero, le doy a cada pieza un valor base. Luego se modifica por la movilidad de la pieza, cuántas (y qué) piezas amenaza y cuántas piezas la amenazan.

Por supuesto, los reyes móviles no son necesariamente buenos al principio del juego, por lo que en especial los valores para ellos un poco.

Esto funciona bastante rápido y puede terminar un juego con la cosecha actual en 3-4 segundos. Parece que hay espacio para subirlo un par de movimientos si es necesario.

actualizar:

• agregando puntuación para "controlar el centro" al principio del juego
• puntajes de casos especiales de rey
• Se corrigió un error de doble puntuación en la simulación de movimiento

package player;

import java.util.*;
import pieces.*;
import controller.*;

public class ThreeMoveMonte extends Player{
    final static int TOSSES = 60;
    Random rand = new Random();

    @Override
    public Move getMove(Board board, Player them){
        List<Move> moves = getMoves(board, getTeam(), 0);
        for(Move move : moves)
            if(gameOver(apply(board, move)))
                return move;

        moves = getMoves(board, getTeam(), TOSSES);
        int highest = Integer.MIN_VALUE;
        Move best = moves.get(0);
        for(Move move : moves){
            Board applied = apply(board, move);
            Move oBest = getBestMove(applied, getOpponent(getTeam()), 0);
            applied = apply(applied, oBest);
            if(!gameOver(applied)){
                Move lBest = getBestMove(applied, getTeam(), TOSSES);
                Board lApplied = apply(applied, lBest);
                int score = eval(lApplied, getTeam());
                if(score > highest){
                    best = move;
                    highest = score;
                }
            }
        }
        return best;
    }

    boolean gameOver(Board board){
        Field[][] fields = board.getFields();
        int kings = 0;
        for(int x=0;x<fields.length;x++)
            for(int y=0;y<fields[x].length;y++){
                Piece p = fields[x][y].getPiece();
                if(p!=null&&p.getType().equals(PieceType.KING))
                    kings++;
            }
        return kings==2?false:true;
    }

    Move getBestMove(Board board, Color color, int breadth){
        int highest = Integer.MIN_VALUE;
        Move best = null;
        List<Move> moves = getMoves(board, color, breadth);
        for(Move move : moves){
            Board applied = apply(board, move);
            int score = eval(applied, color);
            if(score > highest){
                best = move;
                highest = score;
            }
        }
        return best;
    }

    List<Move> getMoves(Board board, Color color, int breadth){
        List<Move> moves = new ArrayList<Move>();
        Set<Piece> pieces = getPiecesOfColor(board, color);
        for(Piece piece : pieces){
            Set<Point> points = piece.getValidDestinationSet(board);
            for(Point point : points){
                moves.add(new Move(piece, point));
            }
        }
        Collections.shuffle(moves);
        if(breadth > 0)
            while(moves.size()>breadth)
                moves.remove(moves.size()-1);
        return moves;
    }

    Board apply(Board board, Move move){
        Board copy = board.copy();
        Piece piece = move.getPiece().copy();
        Point src = piece.getPos(); 
        Point dest = move.getDestination();
        if(piece.getType().equals(PieceType.PAWN)){
            if(piece.getTeam().equals(Color.WHITE)&&dest.getY()==7 || 
                    piece.getTeam().equals(Color.BLACK)&&dest.getY()==0)
                piece = new Queen(piece.getTeam(), piece.getPos());
        }
        piece.setPos(dest);
        copy.getFields()[src.getX()][src.getY()].setPiece(null);
        copy.getFields()[dest.getX()][dest.getY()].setPiece(piece);
        return copy;
    }

    int eval(Board board, Color color){
        int score = 0;
        List<Piece> mine = getPieces(board);
        Field[][] fields = board.getFields();
        for(Piece piece : mine){
            int value = getValueModified(board, piece);

            Set<Point> moves = piece.getValidDestinationSet(board);
            for(Point move : moves){
                int x = move.getX(),y=move.getY();
                if(fields[x][y].hasPiece()){
                    Piece other = fields[x][y].getPiece();
                    if(!other.getTeam().equals(getTeam()))
                        value += getValue(other) / (other.getType()==PieceType.KING ? 1 : 30); 
                }
                if(mine.size()>10)
                    value += (int)(8 - (Math.abs(3.5-x) + Math.abs(3.5-y)));
            }

            int attackerCount = getAttackers(board, piece, false).size();
            if(piece.getType()==PieceType.KING){
                if(attackerCount > 0)
                    value = -value;
            } else {
                for(int i=0;i<attackerCount;i++)
                    value = (value * 90) / 100;
            }
            score += value;
        }

        return score;
    }

    Set<Piece> getPiecesOfColor(Board board, Color color){
        Field[][] fields = board.getFields();
        Set<Piece> out = new HashSet<Piece>();
        for(int x=0;x<fields.length;x++){
            for(int y=0;y<fields[x].length;y++){
                Piece p = fields[x][y].getPiece();
                if(p!=null&&p.getTeam().equals(color))
                        out.add(p);
            }
        }
        return out;
    }

    Set<Piece> getAttackers(Board board, Piece piece, boolean all){
        Set<Piece> out = new HashSet<Piece>();
        Color color = piece.getTeam();
        Set<Piece> others = getPiecesOfColor(board, getOpponent(color));
        if(all)
            others.addAll(getPiecesOfColor(board, color));
        for(Piece other : others){
            if(other.getValidDestinationSet(board).contains(piece.getPos()))
                out.add(other);
        }
        return out;
    }

    Color getOpponent(Color color){
        return color.equals(Color.BLACK)?Color.WHITE:Color.BLACK;
    }

    int[] pieceValues = {100, 500, 300, 320, 880, 1500};
    int getValue(Piece piece){
        return pieceValues[piece.getType().ordinal()];
    }

    int[] maxMoves = {3, 14, 8, 13, 27, 8};
    int getValueModified(Board board, Piece piece){
        int moves = piece.getValidDestinationSet(board).size();
        double value = getValue(piece)*.9;
        double mod = getValue(piece)*.1*((double)moves/maxMoves[piece.getType().ordinal()]);
        if(piece.getType()==PieceType.KING)
            if(getPieces(board).size()>10)
                mod = -mod;

        return (int)(value + mod);
    }
}

Alfa Beta

Lo sentimos, solo por haber transformado y fusionado código de otras fuentes de Internet en este código JAVA. Pero supera a todos los demás oponentes (incluido PieceMaker) ... hasta ahora.

• No hay pedidos de movimientos.
• No hay búsqueda de reposo.
• No hay evaluación de posición.
• Solo la fuerza bruta bruta de la búsqueda alfa beta.
• Utiliza la profundización iterativa solo para la gestión del tiempo.

Y lo siento, por jugar tan aburrido.

package player;

import java.util.Random;
import controller.*;

public class AlphaBeta extends Player {
    private static final int INFINITY = Integer.MAX_VALUE;
    private static final int MAXTIME = 1800; // max time for evaluation
    private static final Random random=new Random();
    private static int seed=1;

    private long time; // time taken this turn
    private int iterativeDepth;
    private Player myOpponent;
    private int best, candidate;

    @Override
    public Move getMove(Board root, Player min) {
        time=System.currentTimeMillis();
        seed++; myOpponent=min; best=0;
        iterative_deepening(root);
        return allMoves(root, this)[best];
    }

    private void iterative_deepening(Board root) {
        try {
            for (iterativeDepth = 2;; iterativeDepth++) {
                alphaBeta(root, -INFINITY, +INFINITY, iterativeDepth, this, myOpponent);
                best=candidate;
            }
        } catch (InterruptedException e) {}
    }

    //http://chessprogramming.wikispaces.com/Alpha-Beta
    private int alphaBeta(Board root, int alpha, int beta, int d, Player max, Player min) throws InterruptedException {
        if ((System.currentTimeMillis() - time) > MAXTIME)  throw new InterruptedException();
        if (d==0 || root.getKing(max) == null) return evaluate(root, d);
        Move[] allMoves = allMoves(root, max);
        Move move;
        for (int m=0; (move = allMoves[m])!=null; m++) {
            Board board = root.copy();
            board.movePiece(move);
            int score = -alphaBeta(board, -beta, -alpha, d - 1, min, max);
            if (score >= beta)
                return beta; // fail hard beta-cutoff
            if (score > alpha) {
                alpha = score; // alpha acts like max in MiniMax
                if (d == iterativeDepth) candidate = m;
            }
        }
        return alpha;
    }

    private int evaluate(Board board, int d) {
        int minmax=2*((iterativeDepth-d)&1)-1;
        int value = 0, king=0;
        Field[][] field = board.getFields();
        for (int x = 0; x < 8; x++) {
            for (int y = 0; y < 8; y++) {
                Piece piece = field[x][y].getPiece();
                if (piece==null) continue;

                int sign=(piece.getTeam()==getTeam())?-minmax:minmax;
                switch (piece.getType()) {
                case PAWN:      value += 1*sign; break;
                case KNIGHT:    value += 3*sign; break;
                case BISHOP:    value += 3*sign; break;
                case ROOK:      value += 5*sign; break;
                case QUEEN:     value += 9*sign; break;
                case KING:      king  += (100-(iterativeDepth-d))*sign; break;
                default: // value += 0;
                }
            }
        }
        return king==0?value:king;
    }

    private Move[] allMoves(Board board, Player player) {
        random.setSeed(seed);
        Move[] move = new Move[200];
        int m=0;
        for (Piece piece : player.getPieces(board)) {
            for (Point point: piece.getValidDestinationSet(board)) {
                // shuffle
                int r=random.nextInt(++m);
                move[m-1]=move[r];
                move[r]=new Move(piece.copy(), point);
            }
        }
        return move;
    }       
}

No es una respuesta, sino una simulación para ayudar

Agregué una nueva clase: GamePanel y edité Game and Controller

No es muy bonito ... todavía. ¿Sabías que Unicode tenía personajes de ajedrez? (¡totalmente increíble!)
Por cierto, necesitas UTF-8 para que se muestren estos personajes. Funcionó para mí, pero no estoy seguro de cómo funcionará en otros sistemas operativos.

Se corrigió el error del final de los juegos (gracias a Tim por señalarlo).

GamePanel:

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.util.ArrayList;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class GamePanel extends JPanel{
    private static final long serialVersionUID = 1L;
    JFrame container;
    Board currentBoard;
    Game currentGame;
    ArrayList<Game> games;
    public GamePanel(ArrayList<Game> Games){
        games = Games;
        currentGame = games.get(0);
        currentBoard = currentGame.allBoards.get(0);
        container = new JFrame();
        container.setSize(new Dimension(500,500));
        container.setMinimumSize(new Dimension(150,150));
        this.setMinimumSize(new Dimension(150,150));
        JButton skipButton = new JButton("skip game");
        skipButton.addMouseListener(new MouseListener(){
            @Override
            public void mouseClicked(MouseEvent arg0) {
                nextGame();
            }
            @Override
            public void mouseEntered(MouseEvent arg0) {
                // TODO Auto-generated method stub

            }
            @Override
            public void mouseExited(MouseEvent arg0) {
                // TODO Auto-generated method stub

            }
            @Override
            public void mousePressed(MouseEvent arg0) {
                // TODO Auto-generated method stub

            }
            @Override
            public void mouseReleased(MouseEvent arg0) {
                // TODO Auto-generated method stub

            }

        });
        JButton undoButton = new JButton("go back");
        undoButton.addMouseListener(new MouseListener(){
            @Override
            public void mouseClicked(MouseEvent e) {
                unStep();
            }

            @Override
            public void mouseEntered(MouseEvent e) {
                // TODO Auto-generated method stub

            }
            @Override
            public void mouseExited(MouseEvent e) {
                // TODO Auto-generated method stub

            }
            @Override
            public void mousePressed(MouseEvent e) {
                // TODO Auto-generated method stub

            }
            @Override
            public void mouseReleased(MouseEvent e) {
                // TODO Auto-generated method stub

            }

        });
        JButton continueButton = new JButton("continue");
        undoButton.setSize(40,40);
        skipButton.setSize(40,40);
        continueButton.setSize(40,40);
        continueButton.addMouseListener(new MouseListener(){
            @Override
            public void mouseClicked(MouseEvent arg0) {
                step();
            }
            @Override
            public void mouseEntered(MouseEvent arg0) { 
            }
            @Override
            public void mouseExited(MouseEvent arg0) {  
            }
            @Override
            public void mousePressed(MouseEvent arg0) {     
            }
            @Override
            public void mouseReleased(MouseEvent arg0) {    
            }
        });
        JPanel buttonPanel = new JPanel();
        buttonPanel.setLayout(new FlowLayout());
        buttonPanel.add(continueButton);
        buttonPanel.add(undoButton);
        buttonPanel.add(skipButton);
        container.setLayout(new BorderLayout());
        container.getContentPane().add(this,BorderLayout.CENTER);
        container.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        container.getContentPane().add(buttonPanel,BorderLayout.NORTH);
        container.setTitle("White: " + currentGame.players[0].getClass().getSimpleName() 
                + " vs "+ "Black: " + currentGame.players[1].getClass().getSimpleName());
        container.setVisible(true);
        container.invalidate();
        container.repaint();
    }
    private void unStep(){
        if(currentBoard!=currentGame.allBoards.get(0)){
            currentBoard=currentGame.allBoards.get(currentGame.allBoards.indexOf(currentBoard)-1);
        }
        container.invalidate();
        container.repaint();
    }
    private void unGame(){
        if(currentGame != games.get(0)){
            currentGame = games.get(games.indexOf(currentGame)-1);
            currentBoard = currentGame.allBoards.get(0);
        }
        container.invalidate();
        container.repaint();
    }
    private void step(){
        if(currentGame.allBoards.indexOf(currentBoard)==currentGame.allBoards.size()-1){
            nextGame();
        }
        else{
            currentBoard = currentGame.allBoards.get(currentGame.allBoards.indexOf(currentBoard)+1);
        }
        container.invalidate();
        container.repaint();
    }
    private void nextGame(){
        container.setTitle("White: " + currentGame.players[0].getClass().getSimpleName() 
                + " vs "+ "Black: " + currentGame.players[1].getClass().getSimpleName());
        if(currentGame != games.get(games.size()-1)){
            currentGame = games.get(games.indexOf(currentGame)+1);
        }
        else{
            //games complete
            container.dispose();
        }
        currentBoard = currentGame.allBoards.get(0);
        container.invalidate();
        container.repaint();
    }
    @Override
    public void paintComponent(Graphics g){
        if(getWidth()>150 && getHeight() > 150){
        int leftBounds,topBounds,width,height;
        topBounds = 50;
        leftBounds = 50;
        if(getWidth() > getHeight()){
            width = (int) (getHeight()-100);
            height = (int) (getHeight()-100);
        }
        else{
            width = (int) (getWidth()-100);
            height = (int) (getWidth()-100);
        }
        //draw grid
        java.awt.Color dark = new java.awt.Color(128, 78, 41);
        java.awt.Color light = new java.awt.Color(250, 223, 173);
        Field[][] feilds = currentBoard.getFields();
        for(int x = leftBounds; x < leftBounds+width-width/8; x+=width/8){
            for(int y = topBounds; y < topBounds+height-height/8; y+=height/8){
                int xPos = (int)Math.round(((double)(x-leftBounds)/(double)width)*8);
                int yPos = (int)Math.round(((double)(y-topBounds)/(double)height)*8);
                String piece = "";
                java.awt.Color stringColor = java.awt.Color.black;
                if(feilds[xPos][yPos].hasPiece()){
                    piece = getPiece(feilds[xPos][yPos].getPiece());
                    if(feilds[xPos][yPos].getPiece().getTeam()==Color.WHITE){stringColor = java.awt.Color.WHITE;}
                }
                if(yPos % 2 == 1){
                    if(xPos % 2 == 1){
                        g.setColor(dark);
                        g.fillRect(x, y, width/8, height/8);
                    }
                    else{
                        g.setColor(light);
                        g.fillRect(x, y, width/8, height/8);
                    }
                }
                else{
                    if(xPos % 2 == 1){
                        g.setColor(light);
                        g.fillRect(x, y, width/8, height/8);
                    }
                    else{
                        g.setColor(dark);
                        g.fillRect(x, y, width/8, height/8);
                    }
                }
                g.setColor(java.awt.Color.black);
                g.setFont(new Font(Font.SANS_SERIF, Font.BOLD, width/8));
                g.drawString(piece, x, y+width/8);
            }
        }
        }

    }
    public String getPiece(Piece p){
        if(p.getTeam() == Color.WHITE){
            if(p.getType() == PieceType.BISHOP){return "\u2657";}
            if(p.getType() == PieceType.PAWN){return "\u2659";}
            if(p.getType() == PieceType.KING){return "\u2654";}
            if(p.getType() == PieceType.QUEEN){return "\u2655";}
            if(p.getType() == PieceType.ROOK){return "\u2656";}
            if(p.getType() == PieceType.KNIGHT){return "\u2658";}
        }
        else{
            if(p.getType() == PieceType.BISHOP){return "\u265D";}
            if(p.getType() == PieceType.PAWN){return "\u265F";}
            if(p.getType() == PieceType.KING){return "\u265A";}
            if(p.getType() == PieceType.QUEEN){return "\u265B";}
            if(p.getType() == PieceType.ROOK){return "\u265C";}
            if(p.getType() == PieceType.KNIGHT){return "\u265E";}
        }
        return p.toString();
    }

}