Version 1.9

README.md

@@ -3,7 +3,7 @@
 A chessengine build in Java that uses the UCI protocol to communicate with graphical interfaces.
 Should be used with a 64 bit JRE for optimal performance.
 The binaries are build using Java 9 and are not compatible with older Java versions.
-Score is about 2950 elo.
+Score is about 3000 elo.
 
 ## Features
 - (magic) bitboards
@@ -25,7 +25,7 @@ Score is about 2950 elo.
 ## Future
 - multi-threading
 - singular extensions
-- 3000 elo!
+- improved king safety
 
 
 _"Simplicity is the soul of efficiency"_       - Austin Freeman -

pom.xml

@@ -8,7 +8,7 @@
 	<!-- artifactId>${engineName}</artifactId -->
 	<artifactId>chess22k</artifactId>
 
-	<version>1.8</version>
+	<version>1.9</version>
 
 	<properties>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

release-notes.txt

@@ -1,3 +1,15 @@
+1.9 - 23-04-2018 - 3000 elo
+- fixed some crashes
+- improved sorting efficiency
+- calculation instead of lookups for pawn move generation
+- simplified SEE
+- fixed movetime UCI command
+- evaluation
+  - improved passed-pawn
+  - long ranged bishop
+  - bad bishop
+
+
 1.8 - 04-03-2018 - 2950 elo
 - generation of pseudo-legal moves (no elo gain but cleaner code)
 - refactored move generation class

src/main/java/nl/s22k/chess/Bitboard.java

@@ -95,6 +95,8 @@ public class Bitboard {
 	public static final long G1_H1 = G1 | H1;
 	public static final long B3_C2 = B3 | C2;
 	public static final long G3_F2 = G3 | F2;
+	public static final long D4_E5 = D4 | E5;
+	public static final long E4_D5 = E4 | D5;
 	public static final long B6_C7 = B6 | C7;
 	public static final long G6_F7 = G6 | F7;
 	public static final long A8_B8 = A8 | B8;
@@ -136,7 +138,10 @@ public class Bitboard {
 	public static final long RANK_78 = RANK_7 | RANK_8;
 	public static final long RANK_234 = RANK_2 | RANK_3 | RANK_4;
 	public static final long RANK_567 = RANK_5 | RANK_6 | RANK_7;
+	public static final long RANK_23456 = RANK_2 | RANK_3 | RANK_4 | RANK_5 | RANK_6;
+	public static final long RANK_34567 = RANK_3 | RANK_4 | RANK_5 | RANK_6 | RANK_7;
 	public static final long RANK_PROMOTION[] = { RANK_7, RANK_2 };
+	public static final long RANK_NON_PROMOTION[] = { ~RANK_PROMOTION[0], ~RANK_PROMOTION[1] };
 
 	// files
 	public static final long FILE_A = A1 | A2 | A3 | A4 | A5 | A6 | A7 | A8;
@@ -164,7 +169,6 @@ public class Bitboard {
 
 	public static final long WHITE_SPACE_ZONE = (RANK_2 | RANK_3 | RANK_4) & (FILE_C | FILE_D | FILE_E | FILE_F);
 	public static final long BLACK_SPACE_ZONE = (RANK_7 | RANK_6 | RANK_5) & (FILE_C | FILE_D | FILE_E | FILE_F);
-	public static final long[] PAWN_2_MOVE_RANK = { RANK_2, RANK_7 };
 
 	public static long getWhitePawnAttacks(final long pawns) {
 		return pawns << 9 & Bitboard.NOT_FILE_H | pawns << 7 & Bitboard.NOT_FILE_A;
@@ -183,9 +187,9 @@ public static long getPawnNeighbours(final long pawns) {
 	 */
 	public static int manhattanCenterDistance(int sq) {
 		int file = sq & 7;
-		int rank = sq >> 3;
-		file ^= (file - 4) >> 8;
-		rank ^= (rank - 4) >> 8;
+		int rank = sq >>> 3;
+		file ^= (file - 4) >>> 8;
+		rank ^= (rank - 4) >>> 8;
 		return (file + rank) & 7;
 	}
 

src/main/java/nl/s22k/chess/CheckUtil.java

@@ -21,14 +21,14 @@ public static long getCheckingPieces(final ChessBoard cb) {
 		return (cb.pieces[cb.colorToMoveInverse][NIGHT] & StaticMoves.KNIGHT_MOVES[kingIndex]
 				| (cb.pieces[cb.colorToMoveInverse][ROOK]|cb.pieces[cb.colorToMoveInverse][QUEEN]) & MagicUtil.getRookMoves(kingIndex, cb.allPieces)
 				| (cb.pieces[cb.colorToMoveInverse][BISHOP]|cb.pieces[cb.colorToMoveInverse][QUEEN]) & MagicUtil.getBishopMoves(kingIndex, cb.allPieces) 
-				| cb.pieces[cb.colorToMoveInverse][PAWN] & StaticMoves.PAWN_ALL_ATTACKS[cb.colorToMove][kingIndex]
+				| cb.pieces[cb.colorToMoveInverse][PAWN] & StaticMoves.PAWN_ATTACKS[cb.colorToMove][kingIndex]
 			);
 	}
 
 	public static long getCheckingPieces(final ChessBoard cb, final int sourcePieceIndex) {
 		switch(sourcePieceIndex) {
 			case PAWN:
-				return cb.pieces[cb.colorToMoveInverse][PAWN] & StaticMoves.PAWN_ALL_ATTACKS[cb.colorToMove][cb.kingIndex[cb.colorToMove]];
+				return cb.pieces[cb.colorToMoveInverse][PAWN] & StaticMoves.PAWN_ATTACKS[cb.colorToMove][cb.kingIndex[cb.colorToMove]];
 			case NIGHT:
 				return cb.pieces[cb.colorToMoveInverse][NIGHT] & StaticMoves.KNIGHT_MOVES[cb.kingIndex[cb.colorToMove]];
 			case BISHOP:
@@ -50,23 +50,15 @@ public static boolean isInCheck(final int kingIndex, final int colorToMove, fina
 		return (enemyPieces[NIGHT] & StaticMoves.KNIGHT_MOVES[kingIndex]
 				| (enemyPieces[ROOK] | enemyPieces[QUEEN]) & MagicUtil.getRookMoves(kingIndex, allPieces)
 				| (enemyPieces[BISHOP] | enemyPieces[QUEEN]) & MagicUtil.getBishopMoves(kingIndex, allPieces) 
-				| enemyPieces[PAWN] & StaticMoves.PAWN_ALL_ATTACKS[colorToMove][kingIndex]
-			)!= 0;
-	}
-
-	public static boolean isInSlidingCheck(final int kingIndex, final long horVerPieces, final long diagPieces, final long allPieces) {
-
-		// put 'super-piece' in kings position
-		return (horVerPieces & MagicUtil.getRookMoves(kingIndex, allPieces)
-				| diagPieces & MagicUtil.getBishopMoves(kingIndex, allPieces) 
+				| enemyPieces[PAWN] & StaticMoves.PAWN_ATTACKS[colorToMove][kingIndex]
 			)!= 0;
 	}
 
 	public static boolean isInCheckIncludingKing(final int kingIndex, final int colorToMove, final long[] enemyPieces, final long allPieces, final int enemyMajorPieces) {
 
 		//TODO
 		if(enemyMajorPieces==0) {
-			return (enemyPieces[PAWN] & StaticMoves.PAWN_ALL_ATTACKS[colorToMove][kingIndex]
+			return (enemyPieces[PAWN] & StaticMoves.PAWN_ATTACKS[colorToMove][kingIndex]
 					| enemyPieces[KING] & StaticMoves.KING_MOVES[kingIndex]
 				)!= 0;
 		}
@@ -75,7 +67,7 @@ public static boolean isInCheckIncludingKing(final int kingIndex, final int colo
 		return (enemyPieces[NIGHT] & StaticMoves.KNIGHT_MOVES[kingIndex]
 				| (enemyPieces[ROOK] | enemyPieces[QUEEN]) & MagicUtil.getRookMoves(kingIndex, allPieces)
 				| (enemyPieces[BISHOP] | enemyPieces[QUEEN]) & MagicUtil.getBishopMoves(kingIndex, allPieces) 
-				| enemyPieces[PAWN] & StaticMoves.PAWN_ALL_ATTACKS[colorToMove][kingIndex]
+				| enemyPieces[PAWN] & StaticMoves.PAWN_ATTACKS[colorToMove][kingIndex]
 				| enemyPieces[KING] & StaticMoves.KING_MOVES[kingIndex]
 			)!= 0;
 	}

src/main/java/nl/s22k/chess/ChessBoard.java

@@ -73,6 +73,7 @@ public final class ChessBoard {
 
 	public final int[] mobilityScore = new int[2];
 	public long passedPawns;
+	public final long[] outposts = new long[2];
 
 	public static ChessBoard getInstance() {
 		return instance;
@@ -441,34 +442,6 @@ public void setPinnedAndDiscoPieces() {
 		}
 	}
 
-	public long getPinnedPieces(final int color, final long allPieces) {
-
-		final int colorInverse = 1 - color;
-		long pinnedPieces = 0;
-
-		// bishop and queen
-		long piece = (pieces[colorInverse][BISHOP] | pieces[colorInverse][QUEEN]) & allPieces & MagicUtil.bishopMovesEmptyBoard[kingIndex[color]];
-		while (piece != 0) {
-			final long checkedPiece = ChessConstants.BISHOP_IN_BETWEEN[kingIndex[color]][Long.numberOfTrailingZeros(piece)] & allPieces;
-			if (Long.bitCount(checkedPiece) == 1) {
-				pinnedPieces |= checkedPiece;
-			}
-			piece &= piece - 1;
-		}
-
-		// rook and queen
-		piece = (pieces[colorInverse][ROOK] | pieces[colorInverse][QUEEN]) & allPieces & MagicUtil.rookMovesEmptyBoard[kingIndex[color]];
-		while (piece != 0) {
-			final long checkedPiece = ChessConstants.ROOK_IN_BETWEEN[kingIndex[color]][Long.numberOfTrailingZeros(piece)] & allPieces;
-			if (Long.bitCount(checkedPiece) == 1) {
-				pinnedPieces |= checkedPiece;
-			}
-			piece &= piece - 1;
-		}
-
-		return pinnedPieces;
-	}
-
 	public void undoMove(int move) {
 
 		final int fromIndex = MoveUtil.getFromIndex(move);
@@ -537,7 +510,7 @@ public void undoMove(int move) {
 
 	public void updateKingValues(final int kingColor, final int index) {
 		kingIndex[kingColor] = index;
-		kingArea[kingColor] = ChessConstants.KING_SAFETY_MASK[kingColor][index];
+		kingArea[kingColor] = ChessConstants.KING_AREA[kingColor][index];
 	}
 
 	public boolean isLegal(final int move) {
@@ -558,12 +531,6 @@ public boolean isLegal(final int move) {
 		return true;
 	}
 
-	public boolean isLegalMove(final int fromIndex, final int toIndex) {
-		// called when king is in check and by killer-move-validity-check
-		return !CheckUtil.isInSlidingCheck(kingIndex[colorToMove], pieces[colorToMoveInverse][ROOK] | pieces[colorToMoveInverse][QUEEN],
-				pieces[colorToMoveInverse][BISHOP] | pieces[colorToMoveInverse][QUEEN], allPieces ^ Util.POWER_LOOKUP[fromIndex] ^ Util.POWER_LOOKUP[toIndex]);
-	}
-
 	private boolean isLegalEvasiveMove(final int fromIndex, final int toIndex) {
 		// called when king is in check and by killer-move-validity-check
 		return !CheckUtil.isInCheck(kingIndex[colorToMove], colorToMove, pieces[colorToMoveInverse],
@@ -621,10 +588,8 @@ public boolean isValidQuietMove(int move) {
 				return false;
 			}
 			break;
-
 		case NIGHT:
 			break;
-
 		case BISHOP:
 			if ((MagicUtil.getBishopMoves(fromIndex, allPieces) & Util.POWER_LOOKUP[toIndex]) == 0) {
 				return false;
@@ -635,13 +600,11 @@ public boolean isValidQuietMove(int move) {
 				return false;
 			}
 			break;
-
 		case QUEEN:
 			if (((MagicUtil.getBishopMoves(fromIndex, allPieces) | MagicUtil.getRookMoves(fromIndex, allPieces)) & Util.POWER_LOOKUP[toIndex]) == 0) {
 				return false;
 			}
 			break;
-
 		case KING:
 			if (MoveUtil.getMoveType(move) == MoveUtil.TYPE_CASTLING) {
 				long castlingIndexes = CastlingUtil.getCastlingIndexes(this);

src/main/java/nl/s22k/chess/ChessConstants.java

@@ -24,7 +24,7 @@ public class ChessConstants {
 	public static final int[] COLOR_FACTOR_8 = { 8, -8 };
 	public static final int[] COLOR_FACTOR_16 = { 16, -16 };
 
-	public static final long[][] KING_SAFETY_MASK = new long[2][64];
+	public static final long[][] KING_AREA = new long[2][64];
 	public static final long[][] KING_PAWN_SHIELD_KINGSIDE_MASK = new long[2][8];
 	public static final long[][] KING_PAWN_SHIELD_QUEENSIDE_MASK = new long[2][8];
 
@@ -176,7 +176,7 @@ public class ChessConstants {
 		// fill passed-pawn-masks
 		for (int i = 0; i < 64; i++) {
 			PASSED_PAWN_MASKS[WHITE][i] = ((Bitboard.FILES[i & 7] | Bitboard.FILES_ADJACENT[i & 7]) & ~Bitboard.RANKS[i / 8]) >>> i << i;
-			PASSED_PAWN_MASKS[BLACK][i] = ((Bitboard.FILES[i & 7] | Bitboard.FILES_ADJACENT[i & 7]) & ~Bitboard.RANKS[i / 8]) << (63 - i) >> (63 - i);
+			PASSED_PAWN_MASKS[BLACK][i] = ((Bitboard.FILES[i & 7] | Bitboard.FILES_ADJACENT[i & 7]) & ~Bitboard.RANKS[i / 8]) << (63 - i) >>> (63 - i);
 		}
 	}
 
@@ -190,32 +190,49 @@ public class ChessConstants {
 		//
 		for (int i = 0; i < 64; i++) {
 			// NEXT
-			KING_SAFETY_MASK[WHITE][i] |= (StaticMoves.KING_MOVES[i] & Bitboard.RANKS[i / 8]) | Util.POWER_LOOKUP[i];
-			KING_SAFETY_MASK[BLACK][i] |= (StaticMoves.KING_MOVES[i] & Bitboard.RANKS[i / 8]) | Util.POWER_LOOKUP[i];
-
-			if (i > 7) {
-				KING_SAFETY_MASK[WHITE][i] |= StaticMoves.KING_MOVES[i] & Bitboard.RANKS[i / 8 - 1];
-				KING_SAFETY_MASK[BLACK][i] |= StaticMoves.KING_MOVES[i] & Bitboard.RANKS[i / 8 - 1];
-				if (i > 15) {
-					KING_SAFETY_MASK[BLACK][i] |= StaticMoves.KING_MOVES[i] >>> 8 & Bitboard.RANKS[i / 8 - 2];
-				}
+			KING_AREA[WHITE][i] |= StaticMoves.KING_MOVES[i] | Util.POWER_LOOKUP[i];
+			KING_AREA[BLACK][i] |= StaticMoves.KING_MOVES[i] | Util.POWER_LOOKUP[i];
+
+			if (i > 15) {
+				KING_AREA[BLACK][i] |= StaticMoves.KING_MOVES[i] >>> 8;
 			}
-			if (i < 56) {
-				KING_SAFETY_MASK[BLACK][i] |= StaticMoves.KING_MOVES[i] & Bitboard.RANKS[i / 8 + 1];
-				KING_SAFETY_MASK[WHITE][i] |= StaticMoves.KING_MOVES[i] & Bitboard.RANKS[i / 8 + 1];
-				if (i < 48) {
-					KING_SAFETY_MASK[WHITE][i] |= StaticMoves.KING_MOVES[i] << 8 & Bitboard.RANKS[i / 8 + 2];
-				}
+
+			if (i < 48) {
+				KING_AREA[WHITE][i] |= StaticMoves.KING_MOVES[i] << 8;
 			}
 		}
 
 		// always 3 wide, even at file 1 and 8
 		for (int i = 0; i < 64; i++) {
 			for (int color = 0; color < 2; color++) {
 				if (i % 8 == 0) {
-					KING_SAFETY_MASK[color][i] |= KING_SAFETY_MASK[color][i + 1];
+					KING_AREA[color][i] |= KING_AREA[color][i + 1];
 				} else if (i % 8 == 7) {
-					KING_SAFETY_MASK[color][i] |= KING_SAFETY_MASK[color][i - 1];
+					KING_AREA[color][i] |= KING_AREA[color][i - 1];
+				}
+			}
+		}
+
+		// always 4 long
+		for (int i = 0; i < 64; i++) {
+			if (i < 8) {
+				KING_AREA[WHITE][i] = KING_AREA[WHITE][i + 8];
+			} else if (i > 47) {
+				if (i > 55) {
+					KING_AREA[WHITE][i] = KING_AREA[WHITE][i - 16];
+				} else {
+					KING_AREA[WHITE][i] = KING_AREA[WHITE][i - 8];
+				}
+			}
+		}
+		for (int i = 0; i < 64; i++) {
+			if (i > 55) {
+				KING_AREA[BLACK][i] = KING_AREA[BLACK][i - 8];
+			} else if (i < 16) {
+				if (i < 8) {
+					KING_AREA[BLACK][i] = KING_AREA[BLACK][i + 16];
+				} else {
+					KING_AREA[BLACK][i] = KING_AREA[BLACK][i + 8];
 				}
 			}
 		}
@@ -225,14 +242,14 @@ public class ChessConstants {
 		// king-pawn-shield masks
 		for (int i = 1; i < 64; i += 8) {
 			// king-side
-			KING_PAWN_SHIELD_KINGSIDE_MASK[WHITE][i / 8] |= KING_SAFETY_MASK[WHITE][i];
-			KING_PAWN_SHIELD_KINGSIDE_MASK[BLACK][i / 8] |= KING_SAFETY_MASK[BLACK][i];
+			KING_PAWN_SHIELD_KINGSIDE_MASK[WHITE][i / 8] |= KING_AREA[WHITE][i];
+			KING_PAWN_SHIELD_KINGSIDE_MASK[BLACK][i / 8] |= KING_AREA[BLACK][i];
 		}
 
 		for (int i = 6; i < 64; i += 8) {
 			// queen-side
-			KING_PAWN_SHIELD_QUEENSIDE_MASK[WHITE][i / 8] |= KING_SAFETY_MASK[WHITE][i];
-			KING_PAWN_SHIELD_QUEENSIDE_MASK[BLACK][i / 8] |= KING_SAFETY_MASK[BLACK][i];
+			KING_PAWN_SHIELD_QUEENSIDE_MASK[WHITE][i / 8] |= KING_AREA[WHITE][i];
+			KING_PAWN_SHIELD_QUEENSIDE_MASK[BLACK][i / 8] |= KING_AREA[BLACK][i];
 		}
 	}