diff --git a/mutalyzer/util.py b/mutalyzer/util.py
index e340ebe5a8d3f113d6c07ac5b04d2a4c8b34983f..237413fbecd1a28ca50e87ea5ad3a213e9d5d154 100644
--- a/mutalyzer/util.py
+++ b/mutalyzer/util.py
@@ -218,6 +218,24 @@ def format_range(first, last):
     return '%i_%i' % (first, last)
 #format_range
 
+def roll_(s, start, end) :
+    """
+    Different (and easier) way of finding the variability of a substring.
+    """
+    # TODO: Start counting at 1, testing, etc.
+
+    l = len(s)
+
+    i = 0
+    while end + i + 1 < l and s[start + i] == s[end + i + 1] :
+        i += 1
+
+    j = 0
+    while start - j and s[start - j - 1] == s[end - j] :
+        j += 1
+
+    return j, i
+#roll
 
 def roll(s, first, last):
     """