- Experimental: attempting to improve the AI choice for all-in assault for battlefield situations where the defender will have several, but not enough, defenders with evasion (e.g. Flying).

- Currently only enabled for the Experimental AI profile for the testing period.

forge-ai/src/main/java/forge/ai/AiAttackController.java

@@ -424,10 +424,21 @@ public class AiAttackController {
 
         final Player opp = this.defendingOpponent;
 
+        CardCollection accountedBlockers = new CardCollection(this.blockers);
         for (Card attacker : attackers) {
-            if (!CombatUtil.canBeBlocked(attacker, this.blockers, null)
+            if (!CombatUtil.canBeBlocked(attacker, accountedBlockers, null)
                     || attacker.hasKeyword("You may have CARDNAME assign its combat damage as though it weren't blocked.")) {
                 unblockedAttackers.add(attacker);
+            } else {
+                if (ai.getController().isAI()) {
+                    AiController aic = ((PlayerControllerAi)ai.getController()).getAi();
+                    if (aic.getBooleanProperty(AiProps.COMBAT_ASSAULT_ATTACK_EVASION_PREDICTION)) {
+                        // Attempt to identify which blockers will already be taken (blocking other things),
+                        // such that Flying, Shadow, Reach, and other mechanics can be properly accounted for.
+                        List<Card> potentialBestBlockers = CombatUtil.getPotentialBestBlockers(attacker, accountedBlockers, null);
+                        accountedBlockers.removeAll(potentialBestBlockers);
+                    }
+                }
             }
         }
 

forge-ai/src/main/java/forge/ai/AiProps.java

@@ -53,7 +53,8 @@ public enum AiProps { /** */
     STRIPMINE_HIGH_PRIORITY_ON_SKIPPED_LANDDROP ("false"),
     TOKEN_GENERATION_ABILITY_CHANCE ("100"), /** */
     TOKEN_GENERATION_ALWAYS_IF_FROM_PLANESWALKER ("true"), /** */
-    TOKEN_GENERATION_ALWAYS_IF_OPP_ATTACKS ("true"); /** */
+    TOKEN_GENERATION_ALWAYS_IF_OPP_ATTACKS ("true"),
+    COMBAT_ASSAULT_ATTACK_EVASION_PREDICTION ("false"); /** */
 
     private final String strDefaultVal;
 

forge-game/src/main/java/forge/game/combat/CombatUtil.java

@@ -624,6 +624,30 @@ public class CombatUtil {
         return canAttackerBeBlockedWithAmount(attacker, blocks, combat);
     }
 
+    public static List<Card> getPotentialBestBlockers(final Card attacker, final List<Card> blockers, final Combat combat) {
+        List<Card> potentialBlockers = Lists.newArrayList();
+        if (blockers.isEmpty() || attacker == null) {
+            return potentialBlockers;
+        }
+
+        for (final Card blocker : blockers) {
+            if (CombatUtil.canBeBlocked(attacker, blocker.getController()) && CombatUtil.canBlock(attacker, blocker)) {
+                potentialBlockers.add(blocker);
+            }
+        }
+
+        int minBlockers = getMinNumBlockersForAttacker(attacker, blockers.get(0).getController());
+
+        CardLists.sortByPowerDesc(potentialBlockers);
+
+        List<Card> minBlockerList = Lists.newArrayList();
+        for (int i = 0; i < minBlockers && i < potentialBlockers.size(); i++) {
+            minBlockerList.add(potentialBlockers.get(i));
+        }
+
+        return minBlockerList;
+    }
+
     /**
      * <p>
      * needsMoreBlockers.
@@ -1077,7 +1101,7 @@ public class CombatUtil {
                 if (defender != null) {
                     return amount >= defender.getCreaturesInPlay().size();
                 }
-                System.out.println("Warning: it was impossible to deduce the defending player in CombatUtil::canAttackerBeBlockedWithAmount, returning 'true' (safest default).");
+                System.out.println("Warning: it was impossible to deduce the defending player in CombatUtil#canAttackerBeBlockedWithAmount, returning 'true' (safest default).");
                 return true;
             }
             if (amount < defender.getCreaturesInPlay().size()) {
@@ -1088,4 +1112,36 @@ public class CombatUtil {
         return true;
     }
 
+    public static int getMinNumBlockersForAttacker(Card attacker, Player defender) {
+        List<String> restrictions = Lists.newArrayList();
+        for (String kw : attacker.getKeywords()) {
+            if (kw.startsWith("CantBeBlockedByAmount")) {
+                restrictions.add(TextUtil.split(kw, ' ', 2)[1]);
+            }
+            if (kw.equals("Menace")) {
+                restrictions.add("LT2");
+            }
+        }
+        int minBlockers = 1;
+        for ( String res : restrictions ) {
+            int operand = Integer.parseInt(res.substring(2));
+            String operator = res.substring(0, 2);
+            if (operator.equals("LT") || operator.equals("GE")) {
+                if (minBlockers < operand) {
+                    minBlockers = operand;
+                }
+            } else if (operator.equals("LE") || operator.equals("GT") || operator.equals("EQ")) {
+                if (minBlockers < operand + 1) {
+                    minBlockers = operand + 1;
+                }
+            }
+        }
+        if (attacker.hasKeyword("CARDNAME can't be blocked unless all creatures defending player controls block it.")) {
+            if (defender != null) {
+                minBlockers = defender.getCreaturesInPlay().size();
+            }
+        }
+
+        return minBlockers;
+    }
 } // end class CombatUtil

forge-gui/res/ai/Cautious.ai

@@ -51,3 +51,7 @@ TOKEN_GENERATION_ABILITY_CHANCE=80
 # Situations where the AI should always use the token-generation abilities if possible
 TOKEN_GENERATION_ALWAYS_IF_FROM_PLANESWALKER=true
 TOKEN_GENERATION_ALWAYS_IF_OPP_ATTACKS=true
+
+# Attempt to predict the number of potential blockers with various forms of evasion when
+# deciding to do an all-in assault attack (Experimental!)
+COMBAT_ASSAULT_EVASION_PREDICTION=false

forge-gui/res/ai/Default.ai

@@ -52,3 +52,6 @@ TOKEN_GENERATION_ABILITY_CHANCE=80
 TOKEN_GENERATION_ALWAYS_IF_FROM_PLANESWALKER=true
 TOKEN_GENERATION_ALWAYS_IF_OPP_ATTACKS=true
 
+# Attempt to predict the number of potential blockers with various forms of evasion when
+# deciding to do an all-in assault attack (Experimental!)
+COMBAT_ASSAULT_EVASION_PREDICTION=false

forge-gui/res/ai/Experimental.ai

@@ -51,3 +51,7 @@ TOKEN_GENERATION_ABILITY_CHANCE=100
 # Situations where the AI should always use the token-generation abilities if possible
 TOKEN_GENERATION_ALWAYS_IF_FROM_PLANESWALKER=true
 TOKEN_GENERATION_ALWAYS_IF_OPP_ATTACKS=true
+
+# Attempt to predict the number of potential blockers with various forms of evasion when
+# deciding to do an all-in assault attack (Experimental!)
+COMBAT_ASSAULT_EVASION_PREDICTION=true

forge-gui/res/ai/Reckless.ai

@@ -51,3 +51,7 @@ TOKEN_GENERATION_ABILITY_CHANCE=80
 # Situations where the AI should always use the token-generation abilities if possible
 TOKEN_GENERATION_ALWAYS_IF_FROM_PLANESWALKER=true
 TOKEN_GENERATION_ALWAYS_IF_OPP_ATTACKS=true
+
+# Attempt to predict the number of potential blockers with various forms of evasion when
+# deciding to do an all-in assault attack (Experimental!)
+COMBAT_ASSAULT_EVASION_PREDICTION=false