diff --git a/server/entertainment_decider/models.py b/server/entertainment_decider/models.py
index 51058c7..765c85c 100644
--- a/server/entertainment_decider/models.py
+++ b/server/entertainment_decider/models.py
@@ -24,6 +24,7 @@ from typing import (
 )
 
 import magic
+import numpy
 import requests
 from pony import orm
 from pony.orm.core import Query as PonyQuery
@@ -276,6 +277,60 @@ PreferenceScoreCompatible = Union[
 ]
 
 
+class ConsideredMediaGenerator:
+    media_list: Dict[int, MediaElement]
+    dependencies: numpy.ndarray
+
+    def __init__(self, media_list: Iterable[MediaElement]) -> None:
+        self.media_list = {elem.id: elem for elem in media_list}
+        max_id = orm.max(elem.id for elem in MediaElement) + 1
+        self.dependencies = numpy.zeros((max_id, max_id), dtype=numpy.bool_)
+        for left_id, right_id in self.__get_data():
+            self.dependencies[left_id, right_id] = True
+
+    def __get_data(self) -> Iterable[Tuple[int, int]]:
+        return db.select(
+            """
+            SELECT left_elem.id AS left_id, right_elem.id AS right_id
+            FROM mediaelement left_elem
+                INNER JOIN mediacollectionlink left_link
+                on left_elem.id = left_link.element
+                    INNER JOIN mediacollection coll
+                        on left_link.collection = coll.id and coll.watch_in_order
+                    INNER JOIN mediacollectionlink right_link
+                        on left_link.collection = right_link.collection
+                    INNER JOIN mediaelement right_elem
+                        on right_link.element = right_elem.id
+            WHERE NOT (left_elem.watched OR left_elem.ignored) AND NOT (right_elem.watched OR right_elem.ignored)
+            AND (left_link.season, left_link.episode, left_elem.release_date, left_elem.id) >
+                (right_link.season, right_link.episode, right_elem.release_date, right_elem.id)
+        """.strip()
+        )
+
+    def __len__(self) -> int:
+        return len(self.media_list)
+
+    def iter_media(self) -> Iterable[MediaElement]:
+        return [
+            elem
+            for elem_id, elem in self.media_list.items()
+            if not self.dependencies[elem_id].any()
+        ]
+
+    def is_considered_id(self, elem_id: int) -> bool:
+        return elem_id in self.media_list and not self.dependencies[elem_id].any()
+
+    def is_considered(self, element: MediaElement) -> bool:
+        return self.is_considered_id(element.id)
+
+    def mark_as_watched_id(self, elem_id: id) -> None:
+        del self.media_list[elem_id]
+        self.dependencies[:, elem_id] = False
+
+    def mark_as_watched(self, element: MediaElement) -> None:
+        return self.mark_as_watched_id(element.id)
+
+
 def generate_preference_list(
     base: PreferenceScore,
     object_gen: Callable[[], List[MediaElement]],