diff --git a/libs/subliminal/subtitle.py b/libs/subliminal/subtitle.py
index eb4a985ef..b78733fb5 100644
--- a/libs/subliminal/subtitle.py
+++ b/libs/subliminal/subtitle.py
@@ -232,39 +232,27 @@ def guess_matches(video, guess, partial=False):
         if video.title and 'title' in guess and sanitize(guess['title']) == sanitize(video.title):
             matches.add('title')
     # release_group
-    if 'release_group' in guess:
-        release_groups = guess["release_group"]
-        if not isinstance(release_groups, types.ListType):
-            release_groups = [release_groups]
-
-        if video.release_group:
-            for release_group in release_groups:
-                if (sanitize_release_group(release_group) in
-                        get_equivalent_release_groups(sanitize_release_group(video.release_group))):
-                    matches.add('release_group')
-                    break
+    if (video.release_group and 'release_group' in guess and
+            sanitize_release_group(guess['release_group']) in
+            get_equivalent_release_groups(sanitize_release_group(video.release_group))):
+        matches.add('release_group')
     # resolution
     if video.resolution and 'screen_size' in guess and guess['screen_size'] == video.resolution:
         matches.add('resolution')
     # format
-    if 'format' in guess:
+    if 'format' in guess and video.format:
         formats = guess["format"]
         if not isinstance(formats, types.ListType):
             formats = [formats]
 
-        if video.format:
-            video_format = video.format
-            if video_format in ("HDTV", "SDTV", "TV"):
-                video_format = "TV"
-                logger.debug("Treating HDTV/SDTV the same")
+        video_formats = video.format
+        if not isinstance(video_formats, types.ListType):
+            video_formats = [video_formats]
 
-            for frmt in formats:
-                if frmt in ("HDTV", "SDTV"):
-                    frmt = "TV"
+        lwr = lambda x: "tv" if x in ("HDTV", "SDTV", "TV") else x.lower()
 
-                if frmt.lower() == video_format.lower():
-                    matches.add('format')
-                    break
+        if set(list(map(lwr, formats))) & set(list(map(lwr, video_formats))):
+            matches.add('format')
     # video_codec
     if video.video_codec and 'video_codec' in guess and guess['video_codec'] == video.video_codec:
         matches.add('video_codec')