diff --git a/src/go/core.py b/src/go/core.py
--- a/src/go/core.py
+++ b/src/go/core.py
@@ -15,9 +15,6 @@ class Go:
 		self._hashes=[]
 		self._record=GameRecord()
 
-	def listMoves(self,diff=[]):
-		return []
-
 	## Executes a move.
 	#
 	#  Doesn't check for kos. Suicide not allowed.
@@ -47,13 +44,15 @@ class Go:
 
 	def undoMove(self,r,c,captures):
 		assert self.board[r][c]==-1*self.toMove, "{0}!={1}".format(self.board[r][c],-1*self.toMove)
-		self.toMove*=-1
-		self.board[r][c]=self.toMove
+
 		if len(captures)>0:
 			self._helper.clear()
-			for (r,c) in captures:
-				self._helper.floodFill(EMPTY,r,c)
-			self._fill(-self.toMove)
+			for (ri,ci) in captures:
+				self._helper.floodFill(EMPTY,ri,ci)
+			self._fill(self.toMove)
+
+		self.board[r][c]=EMPTY
+		self.toMove*=-1
 		self._hashes.pop()
 
 	def transitionMove(self,board):
@@ -79,11 +78,6 @@ class Go:
 			self.board[r][c]=filling
 
 
-def exportBoard(board):
-	substitutions={EMPTY:".", BLACK:"X", WHITE:"O"}
-	return "\n".join("".join(substitutions.get(x,"?") for x in row) for row in board)
-
-
 def isLegalPosition(board):
 	boardSize=len(board)
 	temp=[[None]*boardSize for x in range(boardSize)]