elo: shuffle prop_arena

src/elo.rs

@@ -253,17 +253,16 @@ impl PlayerArena {
     }
 
     fn prop_arena(&mut self, n: usize) {
-        self.play(
-            &(0..self.players.len())
-                .flat_map(|i| {
-                    (0..self.players.len())
-                        .map(move |j| (i, j))
-                        .filter(|(i, j)| i != j)
-                        .collect::<Vec<_>>()
-                })
-                .collect::<Vec<_>>()
-                .repeat(n),
-        );
+        let mut games = (0..self.players.len())
+            .flat_map(|i| {
+                (0..self.players.len())
+                    .map(move |j| (i, j))
+                    .filter(|(i, j)| i != j)
+            })
+            .collect::<Vec<_>>()
+            .repeat(n);
+        games.shuffle(&mut rand::rng());
+        self.play(&games);
     }
 
     fn process_outcome(&mut self, player1: usize, player2: usize, outcome: &Outcomes) {