improvign bot by giving king endgame table

2 files changed, 30 insertions, 8 deletions

diff --git a/src/bot.cpp b/src/bot.cpp
index ef6f647..13e3c57 100644
--- a/src/bot.cpp
+++ b/src/bot.cpp
@@ -208,9 +208,14 @@ static int search(int depth, Game *b, int alpha, int beta, int ply) {
     }
   }
   if (!searchStopped) {
-    const Flag flag = bestScore <= alphaOrig ? UPPERBOUND
-                      : bestScore >= beta    ? LOWERBOUND
-                                             : EXACT;
+
+    Flag flag = EXACT;
+    if (bestScore > beta) {
+      flag = UPPERBOUND;
+    }
+    if (bestScore < alphaOrig) {
+      flag = LOWERBOUND;
+    }
 
     (*b->Transpositions)[gameHash] = {
         .depth = depth, .Eval = bestScore, .flag = flag, .bestMove = bestMove};
@@ -299,7 +304,7 @@ Move GetBestMove(Game *b, int maxDepth, move_options options) {
     int increment = b->turn ? options.wncr : options.bncr;
     double time_remaning = b->turn ? options.wtime : options.btime;
 
-    timeToThingMS = (time_remaning / 20 + increment * 0.8);
+    timeToThingMS = ((time_remaning / 20) + (increment * 0.8));
   }
 
   bool continueSearching = true;
diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index b1fc4f1..d2ee734 100644
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -80,7 +80,19 @@ static std::array<int, 64> KING_TABLE_EARLY = {
     20,  30,  10,  0,   0,   10,  30,  20,  //
 };
 
-int EvaluateBoard(Game *g) {
+static std::array<int, 64> KING_TABLE_LATE =
+    {
+        -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, //
+}
+
+int EvaluateBoard(Game * g) {
   int score = EvaluateBoardForWhite(g);
   return g->turn ? score : score * -1;
 };
@@ -111,7 +123,7 @@ static int ForceKingToEdgeBonus(const Position enemyKing,
 
   return bonus;
 }
-int CountBoardMaterial(Game *g) {
+int CountBoardMaterial(Game *g, bool isEndgame) {
   int score = 0;
 
   uint64_t piece_bitboard = g->PieceBitboard;
@@ -151,7 +163,11 @@ int CountBoardMaterial(Game *g) {
       value += QUEEN_TABLE[RotateBoardForBlack(i, piece.color)];
       break;
     case KING:
-      value = KING_TABLE_EARLY[RotateBoardForBlack(i, piece.color)];
+      if (isEndgame) {
+        value = KING_TABLE_LATE[RotateBoardForBlack(i, piece.color)];
+      } else {
+        value = KING_TABLE_EARLY[RotateBoardForBlack(i, piece.color)];
+      }
       break;
     default:
       break;
@@ -204,9 +220,10 @@ int EvaluateBoardForWhite(Game *g) {
 
   int score = 0;
 
+  bool isEndGame = IsEndgame(g);
   score += CountBoardMaterial(g);
 
-  if (IsEndgame(g)) {
+  if (isEndGame) {
     Position whiteKing = FindKing(g, true);
     Position blackKing = FindKing(g, false);