diff --git a/src/diana/go.py b/src/diana/go.py
--- a/src/diana/go.py
+++ b/src/diana/go.py
@@ -12,6 +12,12 @@ class Go:
 		self.temp = [[]]
 	
 	def move(self, color, y, x):
+		"""Update the board with the specified move.
+
+		:param int color: BLACK or WHITE
+		:param int y: the row number
+		:param int x: the column number
+		:return: True on success, False on an invalid move"""
 		if self.board[x][y] != EMPTY:
 			return False
 
@@ -39,10 +45,10 @@ class Go:
 			return False
 		self.temp[x][y] = True
 
-		return self._flood_fill(color, x - 1, y) or \
-			self._flood_fill(color, x + 1, y) or \
-			self._flood_fill(color, x, y - 1) or \
-			self._flood_fill(color, x, y + 1)
+		return self._flood_fill(color, x-1, y) or \
+			self._flood_fill(color, x+1, y) or \
+			self._flood_fill(color, x, y-1) or \
+			self._flood_fill(color, x, y+1)
 	
 	def _remove(self):
 		for i in range(19):