Ticket #132: gunnar_7_10.12.diff

engine/aftermath.c

@@ -93 +93 @@
  * 4. Extend an invincible string towards an opponent string or an own
  *    non-invincible string.
  * 5. Split a big eyespace of an alive own dragon without invincible
- *    strings into smaller pieces.
+ *    strings into smaller pieces. Do not play self-atari here.
  * 6. Play a liberty of a dead opponent dragon.
  *
  * Steps 2--4 are interleaved to try to optimize the efficiency of the
@@ -437 +437 @@
     if (board[pos] != EMPTY || distance[pos] != -1)
       continue;
 
+    /* Do not play self-atari here. */
+    if (is_self_atari(pos, color))
+      continue;
+    
     memset(mx, 0, sizeof(mx));
     
     for (k = 0; k < 8; k++) {

engine/dragon.c

@@ -310 +310 @@
     if (ON_BOARD(str) && board[str] != EMPTY)
       dragon[str] = dragon[dragon[str].origin];
 
+  identify_thrashing_dragons();
+  
   /* Owl threats. */
   for (str = BOARDMIN; str < BOARDMAX; str++)
     if (ON_BOARD(str) 
@@ -329 +331 @@
         int acode = DRAGON2(str).owl_attack_code;
         int dcode = DRAGON2(str).owl_defense_code;
         int defense_point, second_defense_point;
-        
+
         if (get_level() >= 8
             && !disable_threat_computation
             && (owl_threats 
@@ -418 +420 @@
   semeai();
   time_report(2, "  semeai module", NO_MOVE, 1.0);
   
-  identify_thrashing_dragons();
-
   /* Count the non-dead dragons. */
   lively_white_dragons = 0;
   lively_black_dragons = 0;

engine/owl.c

@@ -2050 +2050 @@
            * attack with this move.
            *
            * If the move is suicide for us, try to find a backfilling
-           * move to play instead.
+           * move to play instead. Do this also if the move is a
+           * send-two-return-one sacrifice.
            */
           const char *name = "defense move";
 
-          if (is_suicide(dpos, other)) {
+          if (is_suicide(dpos, other) || send_two_return_one(dpos, other)) {
             int dpos2;
             for (k = 0; k < 4; k++) {
               if (board[dpos + delta[k]] == other

engine/value_moves.c

@@ -95 +95 @@
   /* Do some thresholding. */
   if (fewlibs > 4)
     fewlibs = 4;
+  if (to_move && is_ko(pos, color, NULL) && fewlibs > 1)
+    fewlibs = 1;
   if (fewlibs == 0 && own_strings == 1)
     own_strings = 0;
 
@@ -160 +162 @@
   for (ii = BOARDMIN; ii < BOARDMAX; ii++) {
     if (!ON_BOARD(ii))
       continue;
+
+    /* Don't consider send-two-return-one moves here. */
+    if (send_two_return_one(ii, color))
+      continue;
     
     for (k = 0; k < MAX_REASONS; k++) {
       int r = move[ii].reason[k];
@@ -3141 +3147 @@
                         + move[pos].reverse_followup_value);
     }
 
-    tot_value += 0.05 * move[pos].secondary_value;
+    tot_value += soft_cap(0.05 * move[pos].secondary_value, 0.4);
     if (move[pos].secondary_value != 0.0)
-      TRACE("  %1m: %f - secondary\n", pos, 0.05 * move[pos].secondary_value);
+      TRACE("  %1m: %f - secondary\n", pos,
+            soft_cap(0.05 * move[pos].secondary_value, 0.4));
 
     if (move[pos].numpos_shape + move[pos].numneg_shape > 0) {
       /* shape_factor has already been computed. */

engine/worm.c

@@ -832 +832 @@
     for (k = 0; k < liberties; k++) {
       int pos = libs[k];
       if (!attack_move_known(pos, str)) {
-        /* Try to attack on the liberty. */
-        if (trymove(pos, other, "make_worms", str)) {
+        /* Try to attack on the liberty. Don't consider
+         * send-two-return-one moves.
+         */
+        if (!send_two_return_one(pos, other)
+            && trymove(pos, other, "make_worms", str)) {
           if (board[str] == EMPTY || attack(str, NULL)) {
             if (board[str] == EMPTY)
               dcode = 0;