diff --git a/src/statebag.py b/src/statebag.py
--- a/src/statebag.py
+++ b/src/statebag.py
@@ -16,19 +16,9 @@ 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
 """
-import random
-
-from util import EMPTY
+from util import EMPTY, hashBoard
 from go.engine import transitionSequence
 
-rand=random.Random()
-rand.seed(361)
-zobristNums=tuple(
-	tuple(
-		tuple(rand.getrandbits(32) for i in range(3)) for c in range(19)
-	) for r in range(19)
-)
-
 
 ## Crude lower bound on edit distance between states.
 def estimateDistance(diff):
@@ -51,11 +41,7 @@ class BoardState:
 		self.diff2Prev=None
 
 	def hash(self):
-		res=0
-		for (r,row) in enumerate(self._board):
-			for (c,item) in enumerate(row):
-				res^=zobristNums[r][c][item+1]
-		return res
+		return hashBoard(self._board)
 
 	def __iter__(self): return iter(self._board)
 
@@ -73,8 +59,7 @@ class BoardState:
 		return res
 
 	def __eq__(self,x):
-		# might want to use hash
-		return self._board==x._board
+		return self.hash()==x.hash()
 
 
 class StateBag: