diff --git a/doc/measures_functions.md b/doc/measures_functions.md
index 255e7bf..f42fb09 100644
--- a/doc/measures_functions.md
+++ b/doc/measures_functions.md
@@ -213,8 +213,8 @@ Name | Description
 ---- | -----------
 extent | A geometry of the extent of the input geometries
 metadata | A JSON array composed of metadata input objects.  Each indicates one desired measure for an output column, and optionally additional parameters about that column
-max_timespan_rank | How many historical time periods to include.  Defaults to 1
-max_boundary_score_rank | How many alternative boundary levels to include.  Defaults to 1
+num_timespan_options | How many historical time periods to include.  Defaults to 1
+num_score_options | How many alternative boundary levels to include.  Defaults to 1
 target_geoms | Target number of geometries.  Boundaries with close to this many objects within `extent` will be ranked highest. 
 
 The schema of the metadata input objects are as follows:
@@ -229,8 +229,8 @@ numer_timespan | The desired timespan for the measurement.  Defaults to most rec
 geom_timespan | The desired timespan for the geometry.  Defaults to timespan matching numer_timespan if left unspecified.
 target_area | Instead of aiming to have `target_geoms` in the area of the geometry passed as `extent`, fill this area.  Unit is square degrees WGS84.  Set this to `0` if you want to use the smallest source geometry for this element of metadata, for example if you're passing in points.
 target_geoms | Override global `target_geoms` for this element of metadata
-max_timespan_rank | Override global `max_timespan_rank` for this element of metadata
-max_score_rank | Override global `max_score_rank` for this element of metadata
+max_timespan_rank | Only include timespans of this recency (for example, `1` is only the most recent timespan). No limit by default
+max_score_rank | Only include boundaries of this relevance (for example, `1` is the most relevant boundary).  Is `1` by default
 
 #### Returns
 
diff --git a/src/pg/sql/41_observatory_augmentation.sql b/src/pg/sql/41_observatory_augmentation.sql
index 710da76..8521a76 100644
--- a/src/pg/sql/41_observatory_augmentation.sql
+++ b/src/pg/sql/41_observatory_augmentation.sql
@@ -102,8 +102,8 @@ $$ LANGUAGE plpgsql STABLE;
 CREATE OR REPLACE FUNCTION cdb_observatory.OBS_GetMeta(
   geom geometry(Geometry, 4326),
   params JSON,
-  max_timespan_rank INTEGER DEFAULT NULL, -- cutoff for timespan ranks when there's ambiguity
-  max_score_rank INTEGER DEFAULT NULL, -- cutoff for geom ranks when there's ambiguity
+  num_timespan_options INTEGER DEFAULT NULL, -- how many timespan options to show
+  num_score_options INTEGER DEFAULT NULL, -- how many score options to show
   target_geoms INTEGER DEFAULT NULL
 )
 RETURNS JSON
@@ -115,11 +115,11 @@ DECLARE
   scores_clause TEXT;
   result JSON;
 BEGIN
-  IF max_timespan_rank IS NULL THEN
-    max_timespan_rank := 1;
+  IF num_timespan_options IS NULL THEN
+    num_timespan_options := 1;
   END IF;
-  IF max_score_rank IS NULL THEN
-    max_score_rank := 1;
+  IF num_score_options IS NULL THEN
+    num_score_options := 1;
   END IF;
 
   numer_filters := (SELECT Array_Agg(val) FILTER (WHERE val IS NOT NULL) FROM (SELECT (JSON_Array_Elements(params))->>'numer_id' val) foo);
@@ -244,6 +244,10 @@ BEGIN
           'numer_id', numer_id,
           'timespan_rank', dense_rank() OVER (PARTITION BY id ORDER BY numer_timespan DESC),
           'score_rank', dense_rank() OVER (PARTITION BY id ORDER BY score DESC),
+          'timespan_rownum', row_number() over
+            (PARTITION BY id, score ORDER BY numer_timespan DESC, Coalesce(denom_id, '')),
+          'score_rownum', row_number() over
+            (PARTITION BY id, numer_timespan ORDER BY score DESC, Coalesce(denom_id, '')),
           'score', scores.score,
           'suggested_name', cdb_observatory.FIRST(meta.suggested_name),
           'numer_aggregate', cdb_observatory.FIRST(meta.numer_aggregate),
@@ -289,8 +293,10 @@ BEGIN
       GROUP BY id, score, numer_id, denom_id, geom_id, numer_timespan
     ) SELECT JSON_AGG(metadata ORDER BY id)
       FROM groups
-      WHERE timespan_rank <= Coalesce((metadata->>'max_timespan_rank')::INTEGER, $4)
-        AND score_rank <= Coalesce((metadata->>'max_score_rank')::INTEGER, $5)
+      WHERE timespan_rank <= Coalesce((metadata->>'max_timespan_rank')::INTEGER, 'infinity'::FLOAT)
+        AND score_rank <= Coalesce((metadata->>'max_score_rank')::INTEGER, 1)
+        AND (metadata->>'timespan_rownum')::INTEGER <= $4
+        AND (metadata->>'score_rownum')::INTEGER <= $5
   $string$, meta_filter_clause, scores_clause)
   INTO result
   USING
@@ -300,8 +306,8 @@ BEGIN
     END,
     target_geoms,
     (SELECT ARRAY(SELECT json_array_elements_text(params))::json[]),
-    max_timespan_rank,
-    max_score_rank, numer_filters, geom_filters
+    num_timespan_options,
+    num_score_options, numer_filters, geom_filters
     ;
   RETURN result;
 END;
diff --git a/src/pg/test/sql/41_observatory_augmentation_test.sql b/src/pg/test/sql/41_observatory_augmentation_test.sql
index 881fc5b..80b1c79 100644
--- a/src/pg/test/sql/41_observatory_augmentation_test.sql
+++ b/src/pg/test/sql/41_observatory_augmentation_test.sql
@@ -336,7 +336,7 @@ FROM meta;
 -- OBS_GetMeta for point completes several partial measures with "best"
 -- metadata, includes geom alternatives if asked
 WITH meta AS (SELECT cdb_observatory.OBS_GetMeta(cdb_observatory._TestPoint(),
-  '[{"numer_id": "us.census.acs.B01001002"}]', null, 2) meta)
+  '[{"numer_id": "us.census.acs.B01001002", "max_score_rank": 2}]', null, 2) meta)
 SELECT
 (meta->0->>'id')::integer = 1 id,
 (meta->0->>'numer_id') = 'us.census.acs.B01001002' numer_id,