Don't keep honor tiles in hand with small number of shanten

project/mahjong/ai/discard.py

@@ -28,7 +28,7 @@ def __init__(self, player, tile_to_discard, waiting, tiles_count):
         self.waiting = waiting
         self.tiles_count = tiles_count
 
-        self._calculate_value()
+        self.calculate_value()
 
     def find_tile_in_hand(self, closed_hand):
         """
@@ -54,15 +54,20 @@ def find_tile_in_hand(self, closed_hand):
 
         return TilesConverter.find_34_tile_in_136_array(self.tile_to_discard, closed_hand)
 
-    def _calculate_value(self):
+    def calculate_value(self):
         # base is 100 for ability to mark tiles as not needed (like set value to 50)
         value = 100
+        honored_value = 20
+
+        # we don't need to keep honor tiles in almost completed hand
+        if self.player.ai.previous_shanten <= 2:
+            honored_value = 0
 
         if is_honor(self.tile_to_discard):
             if self.tile_to_discard in self.player.ai.valued_honors:
                 count_of_winds = [x for x in self.player.ai.valued_honors if x == self.tile_to_discard]
                 # for west-west, east-east we had to double tile value
-                value += 20 * len(count_of_winds)
+                value += honored_value * len(count_of_winds)
         else:
             # suits
             suit_tile_grades = [10, 20, 30, 40, 50, 40, 30, 20, 10]

project/mahjong/ai/main.py

@@ -46,7 +46,11 @@ def discard_tile(self):
         results, shanten = self.calculate_outs(self.player.tiles,
                                                self.player.closed_hand,
                                                self.player.is_open_hand)
+        # we had to update tiles value
+        # because it is related with shanten number
         self.previous_shanten = shanten
+        for result in results:
+            result.calculate_value()
 
         if shanten == 0:
             self.player.in_tempai = True

project/mahjong/ai/tests/tests_discards.py

@@ -198,3 +198,14 @@ def test_keep_aka_dora_in_hand(self):
         # we had to keep red five and discard just 5s
         discarded_tile = player.discard_tile()
         self.assertNotEqual(discarded_tile, FIVE_RED_SOU)
+
+    def test_dont_keep_honor_with_small_number_of_shanten(self):
+        table = Table()
+        player = Player(0, 0, table)
+
+        tiles = self._string_to_136_array(sou='11445', pin='55699', man='246')
+        player.init_hand(tiles)
+        player.draw_tile(self._string_to_136_tile(honors='7'))
+
+        discarded_tile = player.discard_tile()
+        self.assertEqual(self._to_string([discarded_tile]), '7z')