diff --git a/src/statebag.py b/src/statebag.py
--- a/src/statebag.py
+++ b/src/statebag.py
@@ -16,7 +16,7 @@ So we try to find the correct crossover 
 	- remember the better variant
 - linearize the fork back by discarding s'_j-s preceding the crossover and s_j-s following the crossover
 """
-from util import EMPTY, hashBoard
+from util import EMPTY, hashBoard,exportBoard
 from go.engine import transitionSequence
 
 
@@ -43,6 +43,12 @@ class BoardState:
 	def hash(self):
 		return hashBoard(self._board)
 
+	def export(self):
+		return exportBoard(self._board)
+
+	def exportDiff(self,s2):
+		return "vvv\n{0}\n=== {1} ===\n{2}\n^^^".format(self.export(), s2-self, s2.export())
+
 	def __iter__(self): return iter(self._board)
 
 	def __getitem__(self,key): return self._board[key]