diff --git a/IV/Makefile b/IV/Makefile
index 40ee55a..2d048df 100644
--- a/IV/Makefile
+++ b/IV/Makefile
@@ -1,6 +1,6 @@
 SOURCE ?= lithuania-latest.osm.pbf
-#WHERE ?= name='Visinčia' OR name='Šalčia' OR name='Nemunas' OR name='Žeimena' OR name='Lakaja'
-WHERE ?= name='Žeimena' OR name='Lakaja'
+WHERE ?= name='Visinčia' OR name='Šalčia' OR name='Nemunas' OR name='Žeimena' OR name='Lakaja'
+#WHERE ?= name='Žeimena' OR name='Lakaja'
 SLIDES = slides-2021-03-29.pdf
 
 NON_ARCHIVABLES = notes.txt referatui.txt slides-2021-03-29.txt
diff --git a/IV/tests.sql b/IV/tests.sql
index 4606c63..c4759ef 100644
--- a/IV/tests.sql
+++ b/IV/tests.sql
@@ -22,7 +22,7 @@ end
 $$ language plpgsql;
 
 -- to preview this somewhat conveniently in QGIS:
--- stage || '_' || name || ' gen:' || coalesce(gen, 'Ø') || ' nbend:' || lpad(nbend, 2, '0')
+-- stage || '_' || name || ' gen:' || coalesce(gen, 'Ø') || ' nbend:' || lpad(nbend, 4, '0')
 drop table if exists wm_debug;
 create table wm_debug(stage text, name text, gen bigint, nbend bigint, way geometry, props jsonb);
 
diff --git a/IV/wm.sql b/IV/wm.sql
index e053c1b..77d2da5 100644
--- a/IV/wm.sql
+++ b/IV/wm.sql
@@ -330,31 +330,30 @@ $$ language plpgsql;
 
 create function isolated_bends(INOUT bendattrs t_bend_attrs[], dbgname text default null) as $$
 declare
-  isolation_threshold constant real default 0.2; -- if neighbor's curvatures are within, it's isolated
+  isolation_threshold constant real default 0.33; -- if neighbor's curvatures are within, it's isolated
   this real;
+  skip_next bool;
   res t_bend_attrs;
-  prev_i int4;
   i int4;
 begin
-  i = 2;
-  while i < array_length(bendattrs, 1)-1 loop
-    this = bendattrs[i].curvature * isolation_threshold;
-    prev_i = i;
-    if bendattrs[i-1].curvature < this and bendattrs[i+1].curvature < this then
-      raise notice '% %`th bend is isolated', dbgname, i;
-      res = bendattrs[i];
-      res.isolated = true;
-      bendattrs[i] = res;
-      i = i + 2;
+  for i in 2..array_length(bendattrs, 1)-1 loop
+    res = bendattrs[i];
+    if skip_next then
+      skip_next = false;
     else
-      i = i + 1;
+      this = bendattrs[i].curvature * isolation_threshold;
+      if bendattrs[i-1].curvature < this and bendattrs[i+1].curvature < this then
+        res.isolated = true;
+        bendattrs[i] = res;
+        skip_next = true;
+      end if;
     end if;
 
     if dbgname is not null then
       insert into wm_debug (stage, name, nbend, way, props) values(
         'fisolated_bends',
         dbgname,
-        prev_i,
+        i,
         res.bend,
         jsonb_build_object(
           'isolated', res.isolated