Do not iterate when not needed

draftfast/optimizer.py

@@ -69,7 +69,8 @@ def __init__(
                 raise PlayerBanAndLockException(player.name)
 
         self.teams = set([p.team for p in self.players])
-        self.matchups = set([p.matchup for p in self.players])
+        if self.min_matchups:
+            self.matchups = set([p.matchup for p in self.players])
         self.objective = self.solver.Objective()
         self.objective.SetMaximization()
 
@@ -413,7 +414,7 @@ def _set_min_matchups(self):
         generally two for classic sports
         """
         matchups = []
-        if self.min_matchups > 1:
+        if self.min_matchups and self.min_matchups > 1:
             for matchup in self.matchups:
                 if matchup:
                     matchup_var = self.solver.IntVar(0, 1, matchup)

draftfast/settings.py

@@ -107,9 +107,14 @@ def __init__(
         no_defense_against_captain=False,
         showdown_teams=None,
         min_teams=2,
-        min_matchups=1,
+        min_matchups=None,
         custom_rules=None,
     ):
+        """
+        A note on defaults:
+
+        - min_teams 2 - this constraint is common across Classic and Showdown.
+        """
         self.stacks = stacks
         self.existing_rosters = existing_rosters or []
         self.force_combo = force_combo