diff --git a/src/regexp_nfa.c b/src/regexp_nfa.c
index 4fbafcd..475b629 100644
--- a/src/regexp_nfa.c
+++ b/src/regexp_nfa.c
@@ -3956,25 +3956,138 @@
     if (depth > 4)
 	return 1;
 
-    if (c == NFA_SPLIT)
+    switch (c)
     {
-	if (state->out->c == NFA_SPLIT || state->out1->c == NFA_SPLIT)
+	case NFA_SPLIT:
+	    if (state->out->c == NFA_SPLIT || state->out1->c == NFA_SPLIT)
+		/* avoid recursive stuff */
+		return 1;
+	    /* two alternatives, use the lowest failure chance */
+	    l = failure_chance(state->out, depth + 1);
+	    r = failure_chance(state->out1, depth + 1);
+	    return l < r ? l : r;
+
+	case NFA_ANY:
+	    /* matches anything, unlikely to fail */
 	    return 1;
-	l = failure_chance(state->out, depth + 1);
-	r = failure_chance(state->out1, depth + 1);
-	return l < r ? l : r;
-    }
-    if (c == NFA_ANY)
-	return 1;
-    if (c > 0)
-	return 99;
-    if ((c >= NFA_MOPEN && c <= NFA_MOPEN9)
+	case NFA_MATCH:
+	    /* empty match works always */
+	    return 0;
+
+	case NFA_BOL:
+	case NFA_EOL:
+	case NFA_BOF:
+	case NFA_EOF:
+	case NFA_NEWL:
+	    return 99;
+
+	case NFA_BOW:
+	case NFA_EOW:
+	    return 90;
+
+	case NFA_MOPEN:
+	case NFA_MOPEN1:
+	case NFA_MOPEN2:
+	case NFA_MOPEN3:
+	case NFA_MOPEN4:
+	case NFA_MOPEN5:
+	case NFA_MOPEN6:
+	case NFA_MOPEN7:
+	case NFA_MOPEN8:
+	case NFA_MOPEN9:
 #ifdef FEAT_SYN_HL
-	    || (c >= NFA_ZOPEN && c <= NFA_ZOPEN9)
+	case NFA_ZOPEN:
+	case NFA_ZOPEN1:
+	case NFA_ZOPEN2:
+	case NFA_ZOPEN3:
+	case NFA_ZOPEN4:
+	case NFA_ZOPEN5:
+	case NFA_ZOPEN6:
+	case NFA_ZOPEN7:
+	case NFA_ZOPEN8:
+	case NFA_ZOPEN9:
+	case NFA_ZCLOSE:
+	case NFA_ZCLOSE1:
+	case NFA_ZCLOSE2:
+	case NFA_ZCLOSE3:
+	case NFA_ZCLOSE4:
+	case NFA_ZCLOSE5:
+	case NFA_ZCLOSE6:
+	case NFA_ZCLOSE7:
+	case NFA_ZCLOSE8:
+	case NFA_ZCLOSE9:
 #endif
-	    || c == NFA_NOPEN)
-	return failure_chance(state->out, depth + 1);
-    /* something else */
+	case NFA_NOPEN:
+	case NFA_MCLOSE:
+	case NFA_MCLOSE1:
+	case NFA_MCLOSE2:
+	case NFA_MCLOSE3:
+	case NFA_MCLOSE4:
+	case NFA_MCLOSE5:
+	case NFA_MCLOSE6:
+	case NFA_MCLOSE7:
+	case NFA_MCLOSE8:
+	case NFA_MCLOSE9:
+	case NFA_NCLOSE:
+	    return failure_chance(state->out, depth + 1);
+
+	case NFA_BACKREF1:
+	case NFA_BACKREF2:
+	case NFA_BACKREF3:
+	case NFA_BACKREF4:
+	case NFA_BACKREF5:
+	case NFA_BACKREF6:
+	case NFA_BACKREF7:
+	case NFA_BACKREF8:
+	case NFA_BACKREF9:
+#ifdef FEAT_SYN_HL
+	case NFA_ZREF1:
+	case NFA_ZREF2:
+	case NFA_ZREF3:
+	case NFA_ZREF4:
+	case NFA_ZREF5:
+	case NFA_ZREF6:
+	case NFA_ZREF7:
+	case NFA_ZREF8:
+	case NFA_ZREF9:
+#endif
+	    /* backreferences don't match in many places */
+	    return 94;
+
+	case NFA_LNUM_GT:
+	case NFA_LNUM_LT:
+	case NFA_COL_GT:
+	case NFA_COL_LT:
+	case NFA_VCOL_GT:
+	case NFA_VCOL_LT:
+	case NFA_MARK_GT:
+	case NFA_MARK_LT:
+#ifdef FEAT_VISUAL
+	case NFA_VISUAL:
+#endif
+	    /* before/after positions don't match very often */
+	    return 85;
+
+	case NFA_LNUM:
+	    return 90;
+
+	case NFA_CURSOR:
+	case NFA_COL:
+	case NFA_VCOL:
+	case NFA_MARK:
+	    /* specific positions rarely match */
+	    return 98;
+
+	case NFA_COMPOSING:
+	    return 95;
+
+	default:
+	    if (c > 0)
+		/* character match fails often */
+		return 95;
+    }
+
+    /* something else, includes character classes */
     return 50;
 }