Penalize King advance

Advancing the King to before the Pawns now gets penalized, both in the
normal evaluation and in the King Seige term. Impasses because of reaching
the promotion zone are awarded.

diff --git a/dropper.c b/dropper.c
index eb395b9..2ea7144 100644 (file)
--- a/dropper.c
+++ b/dropper.c
@@ -62,6 +62,7 @@ int moveNr;              // part of game state; incremented by MakeMove
 
 int pvStack[MAXPLY*MAXPLY/2];
 int nrRanks, nrFiles, specials, pinCodes, maxDrop, moveSP, pawn, lanceMask, *pvPtr = pvStack, boardEnd, perpLoses, searchNr;
+int  frontier, killZone, impasse, frontierPenalty, killPenalty;
 int rawInts[21*22], pieceValues[96], pieceCode[96];
 signed char   rawChar[32*22], steps[512];
 unsigned char rawByte[102*22], firstDir[64], rawBulk[98], handSlot[97], promoCode[96], aVal[64], vVal[64], rawLocation[96+23], handBulk[96];
@@ -463,6 +464,11 @@ printf("# variant %d: %s\n", v, variants[v].name);
     // board
     ClearBoard();
     boardEnd = specials = 22*nrRanks;
+    frontier = (nrRanks < 7 ? 22 : nrRanks == 7 ? 2*22 : 3*22);
+    killZone = boardEnd - (nrRanks > 6 ? frontier + 2*22 : 0);
+    impasse  = boardEnd - (nrRanks > 6 ? 3*22 : 2*22);
+    frontierPenalty = (nrRanks > 7 ? 2 : 1);
+    killPenalty     = (nrRanks > 7 ? 8 : 2);
 
     for(i=0; i<COLOR; i++) PST[i] = pstData;
 
@@ -509,6 +515,7 @@ printf("# variant %d: %s\n", v, variants[v].name);
        spoiler[7*22+4] = 10;
        spoiler[7*22+7] = 2;
        PST[WHITE+4] = PST[BLACK+4] = kingPST+11; // Queens
+       frontier = 2*22; killZone = 3*22; impasse = boardEnd;
     } else {
        pawnBulk[WHITE] = (nrRanks == 7 ? 1 : 2); // board file considered full when total reaches 2
     }
@@ -710,10 +717,12 @@ Evaluate (int stm, int rights)
     score += ((board[k+22] == WHITE) + (board[k+22+1] == WHITE) + (board[k+22-1] == WHITE))*2;
     score -= !board[k+22] + !board[k+22+1] + !board[k+22-1];
     score -= ((board[k+44] == BLACK) + (board[k+44+1] == BLACK) + (board[k+44-1] == BLACK))*5;
+    if(k >= killZone) score -= 100;
     k = location[WHITE+31];
     score -= ((board[k-22] == BLACK) + (board[k-22+1] == BLACK) + (board[k-22-1] == BLACK))*2;
     score += !board[k-22] + !board[k-22+1] + !board[k-22-1];
     score += ((board[k-44] == WHITE) + (board[k-44+1] == WHITE) + (board[k-44-1] == WHITE))*5;
+    if(k < boardEnd - killZone) score += 100;
     score *= 20;
     score += rightsScore[rights];
     return stm == WHITE ? score : -score;
@@ -825,7 +834,8 @@ MoveGen (int stm, MoveStack *m, int castle)
     m->safety = SAFE(r+1) + SAFE(r-1) + SAFE(r+22) + SAFE(r+21) + SAFE(r+23) + SAFE(r-21) + SAFE(r-22) + SAFE(r-23);
 #   define ESC(X) (board[X] & stm || attacks[X] == c)
     m->escape = 8 - (ESC(r+1) + ESC(r-1) + ESC(r+22) + ESC(r+21) + ESC(r+23) + ESC(r-21) + ESC(r-22) + ESC(r-23));
-
+    if(stm == WHITE) r = boardEnd - 1 - r;
+    m->safety += (r >= 1*22) + frontierPenalty*(r >= frontier) + killPenalty*(r >= killZone) - 5*(r >= impasse);
     m->unsorted = m->firstMove; m->drops = moveSP;
     return 0;
 }