add softmax for mcts root node

AlphaGo/model.py

@@ -124,6 +124,7 @@ class ResNet(object):
             h = residual_block(h, self.is_training)
         self.v = value_head(h, self.is_training)
         self.p = policy_head(h, self.is_training, self.action_num)
+        self.prob = tf.nn.softmax(self.p)
         self.value_loss = tf.reduce_mean(tf.square(self.z - self.v))
         self.policy_loss = tf.reduce_mean(tf.nn.softmax_cross_entropy_with_logits(labels=self.pi, logits=self.p))
 
@@ -161,7 +162,7 @@ class ResNet(object):
                 'The length of history cannot meet the need of the model, given {}, need {}'.format(len(history),
                                                                                                     self.history_length))
         state = self._history2state(history, color)
-        return self.sess.run([tf.nn.softmax(self.p), self.v], feed_dict={self.x: state, self.is_training: False})
+        return self.sess.run([self.prob, self.v], feed_dict={self.x: state, self.is_training: False})
 
     def _history2state(self, history, color):
         """