diff --git a/.gitignore b/.gitignore
index d697b92..8ee6691 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,8 +4,8 @@ leela-zero
 parameters
 *.swp
 *.sublime*
-checkpoints
-checkpoints_origin
+checkpoint
 *.json
 .DS_Store
 data
+.log
diff --git a/AlphaGo/engine.py b/AlphaGo/engine.py
index 8b54470..98e5e61 100644
--- a/AlphaGo/engine.py
+++ b/AlphaGo/engine.py
@@ -183,7 +183,7 @@ class GTPEngine():
             return 'unknown player', False
 
     def cmd_get_score(self, args, **kwargs):
-        return self._game.game_engine.executor_get_score(self._game.board, True), True
+        return self._game.game_engine.executor_get_score(self._game.board), True
 
     def cmd_show_board(self, args, **kwargs):
         return self._game.board, True
@@ -194,4 +194,4 @@ class GTPEngine():
 
 if __name__ == "main":
     game = Game()
-    engine = GTPEngine(game_obj=Game)
+    engine = GTPEngine(game_obj=game)
diff --git a/AlphaGo/game.py b/AlphaGo/game.py
index 8706572..90d0bf0 100644
--- a/AlphaGo/game.py
+++ b/AlphaGo/game.py
@@ -10,12 +10,14 @@ import copy
 import tensorflow as tf
 import numpy as np
 import sys, os
-import go
 import model
 from collections import deque
 sys.path.append(os.path.join(os.path.dirname(__file__), os.path.pardir))
 from tianshou.core.mcts.mcts import MCTS
 
+import go
+import reversi
+
 class Game:
     '''
     Load the real game and trained weights.
@@ -23,23 +25,32 @@ class Game:
     TODO : Maybe merge with the engine class in future, 
     currently leave it untouched for interacting with Go UI.
     '''
-    def __init__(self, size=9, komi=3.75, checkpoint_path=None):
-        self.size = size
-        self.komi = komi
-        self.board = [utils.EMPTY] * (self.size ** 2)
-        self.history = []
-        self.latest_boards = deque(maxlen=8)
-        for _ in range(8):
-            self.latest_boards.append(self.board)
-        self.evaluator = model.ResNet(self.size, self.size**2 + 1, history_length=8)
-        # self.evaluator = lambda state: self.sess.run([tf.nn.softmax(self.net.p), self.net.v],
-        #                                              feed_dict={self.net.x: state, self.net.is_training: False})
-        self.game_engine = go.Go(size=self.size, komi=self.komi)
+    def __init__(self, name="go", checkpoint_path=None):
+        self.name = name
+        if self.name == "go":
+            self.size = 9
+            self.komi = 3.75
+            self.board = [utils.EMPTY] * (self.size ** 2)
+            self.history = []
+            self.history_length = 8
+            self.latest_boards = deque(maxlen=8)
+            for _ in range(8):
+                self.latest_boards.append(self.board)
+            self.game_engine = go.Go(size=self.size, komi=self.komi)
+        elif self.name == "reversi":
+            self.size = 8
+            self.history_length = 1
+            self.game_engine = reversi.Reversi()
+            self.board = self.game_engine.get_board()
+        else:
+            raise ValueError(name + " is an unknown game...")
+
+        self.evaluator = model.ResNet(self.size, self.size ** 2 + 1, history_length=self.history_length)
 
     def clear(self):
         self.board = [utils.EMPTY] * (self.size ** 2)
         self.history = []
-        for _ in range(8):
+        for _ in range(self.history_length):
             self.latest_boards.append(self.board)
 
     def set_size(self, n):
@@ -65,7 +76,11 @@ class Game:
         # this function can be called directly to play the opponent's move
         if vertex == utils.PASS:
             return True
-        res = self.game_engine.executor_do_move(self.history, self.latest_boards, self.board, color, vertex)
+        # TODO this implementation is not very elegant
+        if self.name == "go":
+            res = self.game_engine.executor_do_move(self.history, self.latest_boards, self.board, color, vertex)
+        elif self.name == "reversi":
+            res = self.game_engine.executor_do_move(self.board, color, vertex)
         return res
 
     def think_play_move(self, color):
diff --git a/AlphaGo/go.py b/AlphaGo/go.py
index 9b7e21f..b819c08 100644
--- a/AlphaGo/go.py
+++ b/AlphaGo/go.py
@@ -157,7 +157,7 @@ class Go:
             vertex = self._deflatten(action)
         return vertex
 
-    def _is_valid(self, history_boards, current_board, color, vertex):
+    def _rule_check(self, history_boards, current_board, color, vertex):
         ### in board
         if not self._in_board(vertex):
             return False
@@ -176,30 +176,30 @@ class Go:
 
         return True
 
-    def simulate_is_valid(self, state, action):
+    def _is_valid(self, state, action):
         history_boards, color = state
         vertex = self._action2vertex(action)
         current_board = history_boards[-1]
 
-        if not self._is_valid(history_boards, current_board, color, vertex):
+        if not self._rule_check(history_boards, current_board, color, vertex):
             return False
 
         if not self._knowledge_prunning(current_board, color, vertex):
             return False
         return True
 
-    def simulate_is_valid_list(self, state, action_set):
+    def simulate_get_mask(self, state, action_set):
         # find all the invalid actions
-        invalid_action_list = []
+        invalid_action_mask = []
         for action_candidate in action_set[:-1]:
             # go through all the actions excluding pass
-            if not self.simulate_is_valid(state, action_candidate):
-                invalid_action_list.append(action_candidate)
-        if len(invalid_action_list) < len(action_set) - 1:
-            invalid_action_list.append(action_set[-1])
+            if not self._is_valid(state, action_candidate):
+                invalid_action_mask.append(action_candidate)
+        if len(invalid_action_mask) < len(action_set) - 1:
+            invalid_action_mask.append(action_set[-1])
             # forbid pass, if we have other choices
             # TODO: In fact we should not do this. In some extreme cases, we should permit pass.
-        return invalid_action_list
+        return invalid_action_mask
 
     def _do_move(self, board, color, vertex):
         if vertex == utils.PASS:
@@ -219,7 +219,7 @@ class Go:
         return [history_boards, new_color], 0
 
     def executor_do_move(self, history, latest_boards, current_board, color, vertex):
-        if not self._is_valid(history, current_board, color, vertex):
+        if not self._rule_check(history, current_board, color, vertex):
             return False
         current_board[self._flatten(vertex)] = color
         self._process_board(current_board, color, vertex)
@@ -280,7 +280,7 @@ class Go:
             elif color_estimate < 0:
                 return utils.WHITE
 
-    def executor_get_score(self, current_board, is_unknown_estimation=False):
+    def executor_get_score(self, current_board):
         '''
             is_unknown_estimation: whether use nearby stone to predict the unknown
             return score from BLACK perspective.
@@ -294,10 +294,8 @@ class Go:
                 _board[self._flatten(vertex)] = utils.BLACK
             elif boarder_color == {utils.WHITE}:
                 _board[self._flatten(vertex)] = utils.WHITE
-            elif is_unknown_estimation:
-                _board[self._flatten(vertex)] = self._predict_from_nearby(_board, vertex)
             else:
-                _board[self._flatten(vertex)] =utils.UNKNOWN
+                _board[self._flatten(vertex)] = self._predict_from_nearby(_board, vertex)
         score = 0
         for i in _board:
             if i == utils.BLACK:
@@ -308,3 +306,42 @@ class Go:
 
         return score
 
+if __name__ == "__main__":
+    ### do unit test for Go class
+    pure_test = [
+        0, 1, 0, 1, 0, 1, 0, 0, 0,
+        1, 0, 1, 0, 1, 0, 0, 0, 0,
+        0, 1, 0, 1, 0, 0, 1, 0, 0,
+        0, 0, 1, 0, 0, 1, 0, 1, 0,
+        0, 0, 0, 0, 0, 1, 1, 1, 0,
+        1, 1, 1, 0, 0, 0, 0, 0, 0,
+        1, 0, 1, 0, 0, 1, 1, 0, 0,
+        1, 1, 1, 0, 1, 0, 1, 0, 0,
+        0, 0, 0, 0, 1, 1, 1, 0, 0
+    ]
+
+    pt_qry = [(1, 1), (1, 5), (3, 3), (4, 7), (7, 2), (8, 6)]
+    pt_ans = [True, True, True, True, True, True]
+
+    opponent_test = [
+        0, 1, 0, 1, 0, 1, 0,-1, 1,
+        1,-1, 0,-1, 1,-1, 0, 1, 0,
+        0, 0, 0, 0, 0, 0, 0, 0, 1,
+        1, 1,-1, 0, 1,-1, 1, 0, 0,
+        1, 0, 1, 0, 1, 0, 1, 0, 0,
+        -1,1, 1, 0, 1, 1, 1, 0, 0,
+        0, 1,-1, 0,-1,-1,-1, 0, 0,
+        1, 0, 1, 0,-1, 0,-1, 0, 0,
+        0, 1, 0, 0,-1,-1,-1, 0, 0
+    ]
+    ot_qry = [(1, 1), (1, 5), (2, 9), (5, 2), (5, 6), (8, 6), (8, 2)]
+    ot_ans = [False, False, False, False, False, False, True]
+
+    go = Go(size=9, komi=3.75)
+    for i in range(6):
+        print (go._is_eye(pure_test, utils.BLACK, pt_qry[i]))
+    print("Test of pure eye\n")
+
+    for i in range(7):
+        print (go._is_eye(opponent_test, utils.BLACK, ot_qry[i]))
+    print("Test of eye surrend by opponents\n")
diff --git a/AlphaGo/model.py b/AlphaGo/model.py
index 3cfb900..22e8626 100644
--- a/AlphaGo/model.py
+++ b/AlphaGo/model.py
@@ -1,5 +1,6 @@
 import os
 import time
+import random
 import sys
 import cPickle
 from collections import deque
@@ -104,7 +105,7 @@ class ResNet(object):
         self.window_length = 7000
         self.save_freq = 5000
         self.training_data = {'states': deque(maxlen=self.window_length), 'probs': deque(maxlen=self.window_length),
-                              'winner': deque(maxlen=self.window_length)}
+                              'winner': deque(maxlen=self.window_length), 'length': deque(maxlen=self.window_length)}
 
     def _build_network(self, residual_block_num, checkpoint_path):
         """
@@ -199,15 +200,15 @@ class ResNet(object):
 
         new_file_list = []
         all_file_list = []
-        training_data = {}
+        training_data = {'states': [], 'probs': [], 'winner': []}
+
         iters = 0
         while True:
             new_file_list = list(set(os.listdir(data_path)).difference(all_file_list))
-            if new_file_list:
+            while new_file_list:
                 all_file_list = os.listdir(data_path)
-            new_file_list.sort(
-                key=lambda file: os.path.getmtime(data_path + file) if not os.path.isdir(data_path + file) else 0)
-            if new_file_list:
+                new_file_list.sort(
+                    key=lambda file: os.path.getmtime(data_path + file) if not os.path.isdir(data_path + file) else 0)
                 for file in new_file_list:
                     states, probs, winner = self._file_to_training_data(data_path + file)
                     assert states.shape[0] == probs.shape[0]
@@ -215,32 +216,36 @@ class ResNet(object):
                     self.training_data['states'].append(states)
                     self.training_data['probs'].append(probs)
                     self.training_data['winner'].append(winner)
-                    if len(self.training_data['states']) == self.window_length:
-                        training_data['states'] = np.concatenate(self.training_data['states'], axis=0)
-                        training_data['probs'] = np.concatenate(self.training_data['probs'], axis=0)
-                        training_data['winner'] = np.concatenate(self.training_data['winner'], axis=0)
+                    self.training_data['length'].append(states.shape[0])
+                new_file_list = list(set(os.listdir(data_path)).difference(all_file_list))
 
             if len(self.training_data['states']) != self.window_length:
                 continue
             else:
-                data_num = training_data['states'].shape[0]
-                index = np.arange(data_num)
-                np.random.shuffle(index)
                 start_time = time.time()
+                for i in range(batch_size):
+                    game_num = random.randint(0, self.window_length-1)
+                    state_num = random.randint(0, self.training_data['length'][game_num]-1)
+                    training_data['states'].append(np.expand_dims(self.training_data['states'][game_num][state_num], 0))
+                    training_data['probs'].append(np.expand_dims(self.training_data['probs'][game_num][state_num], 0))
+                    training_data['winner'].append(np.expand_dims(self.training_data['winner'][game_num][state_num], 0))
                 value_loss, policy_loss, reg, _ = self.sess.run(
                     [self.value_loss, self.policy_loss, self.reg, self.train_op],
-                    feed_dict={self.x: training_data['states'][index[:batch_size]],
-                               self.z: training_data['winner'][index[:batch_size]],
-                               self.pi: training_data['probs'][index[:batch_size]],
+                    feed_dict={self.x: np.concatenate(training_data['states'], axis=0),
+                               self.z: np.concatenate(training_data['winner'], axis=0),
+                               self.pi: np.concatenate(training_data['probs'], axis=0),
                                self.is_training: True})
+
                 print("Iteration: {}, Time: {}, Value Loss: {}, Policy Loss: {}, Reg: {}".format(iters,
                                                                                                  time.time() - start_time,
                                                                                                  value_loss,
                                                                                                  policy_loss, reg))
-                iters += 1
                 if iters % self.save_freq == 0:
                     save_path = "Iteration{}.ckpt".format(iters)
                     self.saver.save(self.sess, self.checkpoint_path + save_path)
+                for key in training_data.keys():
+                    training_data[key] = []
+                iters += 1
 
     def _file_to_training_data(self, file_name):
         read = False
@@ -250,7 +255,7 @@ class ResNet(object):
                     file.seek(0)
                     data = cPickle.load(file)
                     read = True
-                    print("{} Loaded".format(file_name))
+                    print("{} Loaded!".format(file_name))
                 except Exception as e:
                     print(e)
                     time.sleep(1)
@@ -276,6 +281,6 @@ class ResNet(object):
         return states, probs, winner
 
 
-if __name__=="__main__":
-    model = ResNet(board_size=9, action_num=82)
+if __name__ == "__main__":
+    model = ResNet(board_size=9, action_num=82, history_length=8)
     model.train("file", data_path="./data/", batch_size=128, checkpoint_path="./checkpoint/")
diff --git a/AlphaGo/play.py b/AlphaGo/play.py
index 3681430..b601ada 100644
--- a/AlphaGo/play.py
+++ b/AlphaGo/play.py
@@ -7,7 +7,6 @@ import time
 import os
 import cPickle
 
-
 class Data(object):
     def __init__(self):
         self.boards = []
diff --git a/AlphaGo/player.py b/AlphaGo/player.py
index 0e3daff..e848d2b 100644
--- a/AlphaGo/player.py
+++ b/AlphaGo/player.py
@@ -34,7 +34,7 @@ if __name__ == '__main__':
 
     daemon = Pyro4.Daemon()                # make a Pyro daemon
     ns = Pyro4.locateNS()                  # find the name server
-    player = Player(role = args.role, engine = engine)
+    player = Player(role=args.role, engine=engine)
     print "Init " + args.role + " player finished"
     uri = daemon.register(player)          # register the greeting maker as a Pyro object
     print "Start on name " + args.role
diff --git a/AlphaGo/reversi.py b/AlphaGo/reversi.py
index 49d0e9a..c086a2c 100644
--- a/AlphaGo/reversi.py
+++ b/AlphaGo/reversi.py
@@ -25,7 +25,6 @@ def find_correct_moves(own, enemy):
     mobility |= search_offset_right(own, enemy, mask, 7)  # Left bottom
     return mobility
 
-
 def calc_flip(pos, own, enemy):
     """return flip stones of enemy by bitboard when I place stone at pos.
 
@@ -34,7 +33,6 @@ def calc_flip(pos, own, enemy):
     :param enemy: bitboard
     :return: flip stones of enemy when I place stone at pos.
     """
-    assert 0 <= pos <= 63, f"pos={pos}"
     f1 = _calc_flip_half(pos, own, enemy)
     f2 = _calc_flip_half(63 - pos, rotate180(own), rotate180(enemy))
     return f1 | rotate180(f2)
@@ -125,27 +123,42 @@ class Reversi:
         self.board = None  # 8 * 8 board with 1 for black, -1 for white and 0 for blank
         self.color = None  # 1 for black and -1 for white
         self.action = None   # number in 0~63
-        self.winner = None
+        # self.winner = None
+        self.black_win = None
 
-    def simulate_is_valid(self, board, color):
+    def get_board(self, black=None, white=None):
+        self.black = black or (0b00001000 << 24 | 0b00010000 << 32)
+        self.white = white or (0b00010000 << 24 | 0b00001000 << 32)
+        self.board = self.bitboard2board() 	
+        return self.board
+
+    def simulate_get_mask(self, state, action_set):
+        history_boards, color = state
+        board = history_boards[-1]
         self.board = board
         self.color = color
         self.board2bitboard()
         own, enemy = self.get_own_and_enemy()
         mobility = find_correct_moves(own, enemy)
         valid_moves = bit_to_array(mobility, 64)
+        valid_moves = np.argwhere(valid_moves)
         valid_moves = list(np.reshape(valid_moves, len(valid_moves)))
-        return valid_moves
+        # TODO it seems that the pass move is not considered
+        invalid_action_mask = []
+        for action in action_set:
+            if action not in valid_moves:
+                invalid_action_mask.append(action)
+        return invalid_action_mask
 
-    def simulate_step_forward(self, board, color, vertex):
-        self.board = board
-        self.color = color
+    def simulate_step_forward(self, state, action):
+        self.board = state[0]
+        self.color = state[1]
         self.board2bitboard()
-        self.vertex2action(vertex)
+        self.action = action
         step_forward = self.step()
         if step_forward:
             new_board = self.bitboard2board()
-            return new_board
+            return [new_board, 0 - self.color], 0
 
     def executor_do_move(self, board, color, vertex):
         self.board = board
@@ -155,20 +168,21 @@ class Reversi:
         step_forward = self.step()
         if step_forward:
             new_board = self.bitboard2board()
-            return new_board
+        for i in range(64):
+        	board[i] = new_board[i]
 
     def executor_get_score(self, board):
         self.board = board
         self._game_over()
-        if self.winner is not None:
-            return self.winner, 0 - self.winner
+        if self.black_win is not None:
+            return self.black_win
         else:
-            ValueError("Game not finished!")
+            raise ValueError("Game not finished!")
 
     def board2bitboard(self):
         count = 1
         if self.board is None:
-            ValueError("None board!")
+            raise ValueError("None board!")
         self.black = 0
         self.white = 0
         for i in range(64):
@@ -200,7 +214,7 @@ class Reversi:
 
     def step(self):
         if self.action < 0 or self.action > 63:
-            ValueError("Wrong action!")
+            raise ValueError("Wrong action!")
         if self.action is None:
             return False
 
@@ -219,6 +233,7 @@ class Reversi:
 
     def _game_over(self):
         # self.done = True
+        '''
         if self.winner is None:
             black_num, white_num = self.number_of_black_and_white
             if black_num > white_num:
@@ -227,9 +242,12 @@ class Reversi:
                 self.winner = -1
             else:
                 self.winner = 0
+        '''
+        if self.black_win is None:
+        	black_num, white_num = self.number_of_black_and_white
+        	self.black_win = black_num - white_num
 
     def illegal_move_to_lose(self, action):
-        logger.warning(f"Illegal action={action}, No Flipped!")
         self._game_over()
 
     def get_own_and_enemy(self):
diff --git a/AlphaGo/self-play.py b/AlphaGo/self-play.py
index 4387b24..dd03b13 100644
--- a/AlphaGo/self-play.py
+++ b/AlphaGo/self-play.py
@@ -79,7 +79,7 @@ while True:
         prob.append(np.array(game.prob).reshape(-1, game.size ** 2 + 1))
     print("Finished")
     print("\n")
-    score = game.game_engine.executor_get_score(game.board, True)
+    score = game.game_engine.executor_get_score(game.board)
     if score > 0:
         winner = utils.BLACK
     else:
diff --git a/AlphaGo/unit_test.py b/AlphaGo/unit_test.py
deleted file mode 100644
index 7a33b8e..0000000
--- a/AlphaGo/unit_test.py
+++ /dev/null
@@ -1,266 +0,0 @@
-import numpy as np
-import sys
-from game import Game
-from engine import GTPEngine
-import utils
-import time
-import copy
-import network_small
-import tensorflow as tf
-from collections import deque
-from tianshou.core.mcts.mcts import MCTS
-
-DELTA = [[1, 0], [-1, 0], [0, -1], [0, 1]]
-CORNER_OFFSET = [[-1, -1], [-1, 1], [1, 1], [1, -1]]
-
-class GoEnv:
-    def __init__(self, size=9, komi=6.5):
-        self.size = size
-        self.komi = komi
-        self.board = [utils.EMPTY] * (self.size * self.size)
-        self.history = deque(maxlen=8)
-
-    def _set_board(self, board):
-        self.board = board
-
-    def _flatten(self, vertex):
-        x, y = vertex
-        return (x - 1) * self.size + (y - 1)
-
-    def _bfs(self, vertex, color, block, status, alive_break):
-        block.append(vertex)
-        status[self._flatten(vertex)] = True
-        nei = self._neighbor(vertex)
-        for n in nei:
-            if not status[self._flatten(n)]:
-                if self.board[self._flatten(n)] == color:
-                    self._bfs(n, color, block, status, alive_break)
-
-    def _find_block(self, vertex, alive_break=False):
-        block = []
-        status = [False] * (self.size * self.size)
-        color = self.board[self._flatten(vertex)]
-        self._bfs(vertex, color, block, status, alive_break)
-
-        for b in block:
-            for n in self._neighbor(b):
-                if self.board[self._flatten(n)] == utils.EMPTY:
-                    return False, block
-        return True, block
-
-    def _is_qi(self, color, vertex):
-        nei = self._neighbor(vertex)
-        for n in nei:
-            if self.board[self._flatten(n)] == utils.EMPTY:
-                return True
-
-        self.board[self._flatten(vertex)] = color
-        for n in nei:
-            if self.board[self._flatten(n)] == utils.another_color(color):
-                can_kill, block = self._find_block(n)
-                if can_kill:
-                    self.board[self._flatten(vertex)] = utils.EMPTY
-                    return True
-
-        ### avoid suicide
-        can_kill, block = self._find_block(vertex)
-        if can_kill:
-            self.board[self._flatten(vertex)] = utils.EMPTY
-            return False
-
-        self.board[self._flatten(vertex)] = utils.EMPTY
-        return True
-
-    def _check_global_isomorphous(self, color, vertex):
-        ##backup
-        _board = copy.copy(self.board)
-        self.board[self._flatten(vertex)] = color
-        self._process_board(color, vertex)
-        if self.board in self.history:
-            res = True
-        else:
-            res = False
-
-        self.board = _board
-        return res
-
-    def _in_board(self, vertex):
-        x, y = vertex
-        if x < 1 or x > self.size: return False
-        if y < 1 or y > self.size: return False
-        return True
-
-    def _neighbor(self, vertex):
-        x, y = vertex
-        nei = []
-        for d in DELTA:
-            _x = x + d[0]
-            _y = y + d[1]
-            if self._in_board((_x, _y)):
-                nei.append((_x, _y))
-        return nei
-
-    def _corner(self, vertex):
-        x, y = vertex
-        corner = []
-        for d in CORNER_OFFSET:
-            _x = x + d[0]
-            _y = y + d[1]
-            if self._in_board((_x, _y)):
-                corner.append((_x, _y))
-        return corner
-
-    def _process_board(self, color, vertex):
-        nei = self._neighbor(vertex)
-        for n in nei:
-            if self.board[self._flatten(n)] == utils.another_color(color):
-                can_kill, block = self._find_block(n, alive_break=True)
-                if can_kill:
-                    for b in block:
-                        self.board[self._flatten(b)] = utils.EMPTY
-
-    def _find_group(self, start):
-        color = self.board[self._flatten(start)]
-        #print ("color : ", color)
-        chain = set()
-        frontier = [start]
-        while frontier:
-            current = frontier.pop()
-            #print ("current : ", current)
-            chain.add(current)
-            for n in self._neighbor(current):
-                #print n, self._flatten(n), self.board[self._flatten(n)],
-                if self.board[self._flatten(n)] == color and not n in chain:
-                    frontier.append(n)
-        return chain
-
-    def _is_eye(self, color, vertex):
-        nei = self._neighbor(vertex)
-        cor = self._corner(vertex)
-        ncolor = {color == self.board[self._flatten(n)] for n in nei}
-        if False in ncolor:
-            #print "not all neighbors are in same color with us"
-            return False
-        if set(nei) < self._find_group(nei[0]):
-            #print "all neighbors are in same group and same color with us"
-            return True
-        else:
-            opponent_number = [self.board[self._flatten(c)] for c in cor].count(-color)
-            opponent_propotion = float(opponent_number) / float(len(cor))
-            if opponent_propotion < 0.5:
-                #print "few opponents, real eye"
-                return True
-            else:
-                #print "many opponents, fake eye"
-                return False
-
-    # def is_valid(self, color, vertex):
-    def is_valid(self, state, action):
-        # state is the play board, the shape is [1, 9, 9, 17]
-        if action == self.size * self.size:
-            vertex = (0, 0)
-        else:
-            vertex = (action / self.size + 1, action % self.size + 1)
-        if state[0, 0, 0, -1] == utils.BLACK:
-            color = utils.BLACK
-        else:
-            color = utils.WHITE
-        self.history.clear()
-        for i in range(8):
-            self.history.append((state[:, :, :, i] - state[:, :, :, i + 8]).reshape(-1).tolist())
-        self.board = copy.copy(self.history[-1])
-        ### in board
-        if not self._in_board(vertex):
-            return False
-
-        ### already have stone
-        if not self.board[self._flatten(vertex)] == utils.EMPTY:
-            # print(np.array(self.board).reshape(9, 9))
-            # print(vertex)
-            return False
-
-        ### check if it is qi
-        if not self._is_qi(color, vertex):
-            return False
-
-        ### check if it is an eye of yourself
-        ### assumptions : notice that this judgement requires that the state is an endgame
-        #if self._is_eye(color, vertex):
-        #    return False
-
-        if self._check_global_isomorphous(color, vertex):
-            return False
-
-        return True
-
-    def do_move(self, color, vertex):
-        if vertex == utils.PASS:
-            return True
-
-        id_ = self._flatten(vertex)
-        if self.board[id_] == utils.EMPTY:
-            self.board[id_] = color
-            self.history.append(copy.copy(self.board))
-            return True
-        else:
-            return False
-
-    def step_forward(self, state, action):
-        if state[0, 0, 0, -1] == 1:
-            color = 1
-        else:
-            color = -1
-        if action == 81:
-            vertex = (0, 0)
-        else:
-            vertex = (action % 9 + 1, action / 9 + 1)
-        # print(vertex)
-        # print(self.board)
-        self.board = (state[:, :, :, 7] - state[:, :, :, 15]).reshape(-1).tolist()
-        self.do_move(color, vertex)
-        new_state = np.concatenate(
-            [state[:, :, :, 1:8], (np.array(self.board) == 1).reshape(1, 9, 9, 1),
-             state[:, :, :, 9:16], (np.array(self.board) == -1).reshape(1, 9, 9, 1),
-             np.array(1 - state[:, :, :, -1]).reshape(1, 9, 9, 1)],
-            axis=3)
-        return new_state, 0
-
-
-pure_test = [
-    0, 1, 0, 1, 0, 1, 0, 0, 0,
-    1, 0, 1, 0, 1, 0, 0, 0, 0,
-    0, 1, 0, 1, 0, 0, 1, 0, 0,
-    0, 0, 1, 0, 0, 1, 0, 1, 0,
-    0, 0, 0, 0, 0, 1, 1, 1, 0,
-    1, 1, 1, 0, 0, 0, 0, 0, 0,
-    1, 0, 1, 0, 0, 1, 1, 0, 0,
-    1, 1, 1, 0, 1, 0, 1, 0, 0,
-    0, 0, 0, 0, 1, 1, 1, 0, 0
-]
-
-pt_qry = [(1, 1), (1, 5), (3, 3), (4, 7), (7, 2), (8, 6)]
-pt_ans = [True, True, True, True, True, True]
-
-opponent_test = [
-    0, 1, 0, 1, 0, 1, 0,-1, 1,
-    1,-1, 0,-1, 1,-1, 0, 1, 0,
-    0, 0, 0, 0, 0, 0, 0, 0, 1,
-    1, 1,-1, 0, 1,-1, 1, 0, 0,
-    1, 0, 1, 0, 1, 0, 1, 0, 0,
-   -1, 1, 1, 0, 1, 1, 1, 0, 0,
-    0, 1,-1, 0,-1,-1,-1, 0, 0,
-    1, 0, 1, 0,-1, 0,-1, 0, 0,
-    0, 1, 0, 0,-1,-1,-1, 0, 0
-]
-ot_qry = [(1, 1), (1, 5), (2, 9), (5, 2), (5, 6), (8, 2), (8, 6)]
-ot_ans = [False, False, False, False, False, True, False]
-
-#print (ge._find_group((6, 1)))
-#print ge._is_eye(utils.BLACK, pt_qry[0])
-ge = GoEnv()
-ge._set_board(pure_test)
-for i in range(6):
-    print (ge._is_eye(utils.BLACK, pt_qry[i]))
-ge._set_board(opponent_test)
-for i in range(7):
-    print (ge._is_eye(utils.BLACK, ot_qry[i]))
diff --git a/tianshou/core/mcts/mcts.py b/tianshou/core/mcts/mcts.py
index 8bb5f06..e8f3709 100644
--- a/tianshou/core/mcts/mcts.py
+++ b/tianshou/core/mcts/mcts.py
@@ -73,7 +73,7 @@ class UCTNode(MCTSNode):
     def valid_mask(self, simulator):
         # let all invalid actions be illeagel in mcts
         if self.mask is None:
-            self.mask = simulator.simulate_is_valid_list(self.state, range(self.action_num))
+            self.mask = simulator.simulate_get_mask(self.state, range(self.action_num))
         self.ucb[self.mask] = -float("Inf")