diff --git a/script.py b/script.py
index a1c80e2..bbcc5c8 100644
--- a/script.py
+++ b/script.py
@@ -354,25 +354,6 @@ def filter_det_dont_care(self):
 
         self.eval_log += " (" + str(len(self.det_dont_care_indices)) + " don't care)\n" if len(self.det_dont_care_indices) > 0 else "\n"
 
-    def one_to_one_match(self, row, col):
-        """One-to-One match condition"""
-        cont = 0
-        for j in range(len(self.area_precision_matrix[0])):
-            if sum(self.pcc_count_matrix[row][j]) > 0 and self.area_precision_matrix[row, j] >= PARAMS.AREA_PRECISION_CONSTRAINT:
-                cont = cont + 1
-        if cont != 1:
-            return False
-        cont = 0
-        for i in range(len(self.area_precision_matrix)):
-            if sum(self.pcc_count_matrix[i][col]) > 0 and self.area_precision_matrix[i, col] >= PARAMS.AREA_PRECISION_CONSTRAINT:
-                cont = cont + 1
-        if cont != 1:
-            return False
-
-        if sum(self.pcc_count_matrix[row][col]) > 0 and self.area_precision_matrix[row, col] >= PARAMS.AREA_PRECISION_CONSTRAINT:
-            return True
-        return False
-
 
     def one_to_many_match(self, gt_id):
         """One-to-Many match condition"""
@@ -408,13 +389,19 @@ def many_to_one_match(self, det_id):
     def calc_match_matrix(self):
         """Calculate match matrix with PCC counting matrix information."""
         self.eval_log += "Find one-to-one matches\n"
-        for gt_id in range(len(self.gt_boxes)):
-            for det_id in range(len(self.det_boxes)):
-                if gt_id not in self.gt_dont_care_indices and det_id not in self.det_dont_care_indices:
-                    match = self.one_to_one_match(gt_id, det_id)
-                    if match:
-                        self.pairs.append({'gt': [gt_id], 'det': [det_id], 'type': 'OO'})
-                        self.eval_log += "Match GT #{} with Det #{}\n".format(gt_id, det_id)
+        single_gt_ids = [gt_id for gt_id in range(len(self.gt_boxes)) \
+                         if gt_id not in self.gt_dont_care_indices \
+                         and np.sum((np.sum(self.pcc_count_matrix[gt_id], axis=-1) > 0)
+                                   & (self.area_precision_matrix[gt_id] >= PARAMS.AREA_PRECISION_CONSTRAINT)) == 1]
+        single_det_ids = [det_id for det_id in range(len(self.det_boxes)) \
+                          if det_id not in self.det_dont_care_indices \
+                          and np.sum((np.array([sum(i_arr[det_id]) for i_arr in self.pcc_count_matrix]) > 0)
+                                    * (self.area_precision_matrix[:, det_id] >= PARAMS.AREA_PRECISION_CONSTRAINT)) == 1]
+        for gt_id in single_gt_ids:
+            for det_id in single_det_ids:
+                if sum(self.pcc_count_matrix[gt_id][det_id]) > 0 and self.area_precision_matrix[gt_id, det_id] >= PARAMS.AREA_PRECISION_CONSTRAINT:
+                    self.pairs.append({'gt': [gt_id], 'det': [det_id], 'type': 'OO'})
+                    self.eval_log += "Match GT #{} with Det #{}\n".format(gt_id, det_id)
 
         # one-to-many match
         self.eval_log += "Find one-to-many matches\n"