diff --git a/src/PlayersCollection.php b/src/PlayersCollection.php
index c450328..b06d562 100644
--- a/src/PlayersCollection.php
+++ b/src/PlayersCollection.php
@@ -8,7 +8,7 @@
  * Class PlayersCollection
  * @package SecretSanta
  */
-class PlayersCollection implements \Iterator, \Countable
+class PlayersCollection implements \Countable
 {
     /** @var Player[] */
     private $players = [];
@@ -29,10 +29,15 @@ public function addPlayer(Player $player)
     /**
      * @param Player $player
      * @param Player $couple
+     * @throws PlayersCollectionException
      */
     public function addCouple(Player $player, Player $couple)
     {
-        if (!$this->isDuplicatePlayer($player) && !$this->isDuplicatePlayer($couple)) {
+        if (!$this->areDifferentPlayers($player, $couple)) {
+            throw  new PlayersCollectionException('The couple can not be the same player');
+        }
+
+        if (!$this->isDuplicatePlayer($player) && !$this->isDuplicatePlayer($couple) ) {
             $this->players[$player->id()] = $player;
             $this->players[$couple->id()] = $couple;
 
@@ -102,6 +107,14 @@ public function areExclude(Player $player, Player $player2)
         return false;
     }
 
+    /**
+     * @return int
+     */
+    public function count()
+    {
+        return count($this->players);
+    }
+
     /**
      * @return int
      */
@@ -125,6 +138,16 @@ private function isDuplicatePlayer(Player $player)
         return false;
     }
 
+    /**
+     * @param Player $player
+     * @param Player $otherPlayer
+     * @return bool
+     */
+    private function areDifferentPlayers(Player $player, Player $otherPlayer)
+    {
+        return $player->id() != $otherPlayer->id();
+    }
+
     /**
      * @param array $list
      * @return array
@@ -157,52 +180,4 @@ private function forceShuffle($list)
 
         return $shuffleList;
     }
-
-    /**
-     * @return Player
-     */
-    public function current()
-    {
-        return current($this->players);
-    }
-
-    /**
-     * @return void Any returned value is ignored.
-     */
-    public function next()
-    {
-        next($this->players);
-    }
-
-    /**
-     * @return int
-     */
-    public function key()
-    {
-        return key($this->players);
-    }
-
-    /**
-     * @return bool
-     */
-    public function valid()
-    {
-        return ($this->current() !== false);
-    }
-
-    /**
-     * @return void Any returned value is ignored.
-     */
-    public function rewind()
-    {
-        reset($this->players);
-    }
-
-    /**
-     * @return int
-     */
-    public function count()
-    {
-        return count($this->players);
-    }
 }
\ No newline at end of file
diff --git a/src/SecretSanta.php b/src/SecretSanta.php
index 6864161..3211be6 100644
--- a/src/SecretSanta.php
+++ b/src/SecretSanta.php
@@ -53,7 +53,7 @@ public function addCouple($name, $email, $coupleName, $coupleEmail)
     }
 
     /**
-     * @return PlayersCollection
+     * @return Player[]
      * @throws SecretSantaException
      */
     public function play()
@@ -61,15 +61,11 @@ public function play()
         try {
             $this->combinePlayers();
 
-            return $this->players;
+            return $this->associatePlayers();
         } catch (SecretSantaException $exception) {
             throw  $exception;
         } catch (\Exception $exception) {
-            throw new SecretSantaException(
-                'Error during play, impossible to find secret santa, try again',
-                0,
-                $exception
-            );
+            throw new SecretSantaException('Error during play, impossible to find secret santa, try again');
         }
     }
 
@@ -84,29 +80,51 @@ private function combinePlayers()
 
         $retry = count($this->players) + $this->players->countExcludePlayers();
 
-        while (!$this->isValidCombination() && $retry > 0 ) {
-            $this->combination = [];
-            $secretPlayers = $this->players->shufflePlayers();
-            foreach ($this->players as $playerId => $player) {
-                foreach ($secretPlayers as $secretPlayer) {
-                    if ($player->id() != $secretPlayer->id() && !$this->players->areExclude($player, $secretPlayer)) {
-                        if (!in_array($secretPlayer->id(), $this->combination)) {
-                            $player->setSecretSanta($secretPlayer);
-                            $this->combination[$player->id()] = $secretPlayer->id();
-                            unset ($secretPlayers[$secretPlayer->id()]);
-                            break;
-                        }
-                    }
-                }
-            }
+        while (!$this->tryMatchSecretSantaPlayers() && $retry > 0 ) {
             $retry--;
         }
 
-        if (!$this->isValidCombination() && $retry <= 0) {
+        if (!$this->isValidCombination()) {
             throw new SecretSantaException("Not enough players to play");
         }
     }
 
+    /**
+     * @return bool
+     */
+    private function tryMatchSecretSantaPlayers()
+    {
+        $this->combination = [];
+        $secretPlayers = $this->players->shufflePlayers();
+        foreach ($this->players->players() as $playerId => $player) {
+            foreach ($secretPlayers as $secretPlayer) {
+                if ($this->isValidSecretSanta($player, $secretPlayer)) {
+                    $this->combination[$player->id()] = $secretPlayer->id();
+                    unset ($secretPlayers[$secretPlayer->id()]);
+                    break;
+                }
+            }
+        }
+
+        return $this->isValidCombination();
+    }
+
+    /**
+     * @param Player $player
+     * @param Player $secretPlayer
+     * @return bool
+     */
+    private function isValidSecretSanta($player, $secretPlayer)
+    {
+        if ($player->id() != $secretPlayer->id() && !$this->players->areExclude($player, $secretPlayer)) {
+            if (!in_array($secretPlayer->id(), $this->combination)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
     /**
      * @return bool
      */
@@ -114,4 +132,15 @@ private function isValidCombination()
     {
         return count($this->combination) > 0 && count($this->combination) == count($this->players);
     }
+
+    private function associatePlayers()
+    {
+        foreach ($this->combination as $playerId => $secretSantaId) {
+            $this->players->player($playerId)->setSecretSanta(
+                $this->players->player($secretSantaId)
+            );
+        }
+
+        return $this->players->players();
+    }
 }
diff --git a/tests/PlayersCollectionTest.php b/tests/PlayersCollectionTest.php
index 00d3503..0309302 100644
--- a/tests/PlayersCollectionTest.php
+++ b/tests/PlayersCollectionTest.php
@@ -43,6 +43,30 @@ public function testDuplicatePlayer()
         $playersCollection->addPlayer($player);
     }
 
+    /**
+     * @expectedException \SecretSanta\Exceptions\PlayersCollectionException
+     */
+    public function testDuplicatePlayerInCouple()
+    {
+        $expectedPlayer = Player::create('name', 'email@email.com');
+        $expectedCouple = Player::create('nameCouple', 'emailCouple@email.com');
+
+        $playersCollection = new PlayersCollection();
+        $playersCollection->addPlayer($expectedPlayer);
+        $playersCollection->addCouple($expectedPlayer, $expectedCouple);
+    }
+
+    /**
+     * @expectedException \SecretSanta\Exceptions\PlayersCollectionException
+     */
+    public function testSamePlayerInCouple()
+    {
+        $expectedPlayer = Player::create('name', 'email@email.com');
+
+        $playersCollection = new PlayersCollection();
+        $playersCollection->addCouple($expectedPlayer, $expectedPlayer);
+    }
+
     public function testAddCouple()
     {
         $expectedPlayer = Player::create('name', 'email@email.com');
diff --git a/tests/SecretSantaTest.php b/tests/SecretSantaTest.php
index 5f720a1..ce29c80 100644
--- a/tests/SecretSantaTest.php
+++ b/tests/SecretSantaTest.php
@@ -20,6 +20,38 @@ public function testPlayerAndCouple()
         $secretSanta->play();
     }
 
+    /**
+     * @expectedException \SecretSanta\Exceptions\PlayersCollectionException
+     */
+    public function testSameTwoPlayers()
+    {
+        $secretSanta = new SecretSanta();
+
+        $secretSanta->addPlayer('Player', 'player@email.com');
+        $secretSanta->addPlayer('Player', 'player@email.com');
+    }
+
+    /**
+     * @expectedException \SecretSanta\Exceptions\PlayersCollectionException
+     */
+    public function testSameTwoCouplesHimself()
+    {
+        $secretSanta = new SecretSanta();
+
+        $secretSanta->addCouple('Player', 'player@email.com', 'Player', 'player@email.com');
+    }
+
+    /**
+     * @expectedException \SecretSanta\Exceptions\PlayersCollectionException
+     */
+    public function testSameTwoCouples()
+    {
+        $secretSanta = new SecretSanta();
+
+        $secretSanta->addCouple('Player', 'player@email.com', 'Couple', 'couple@email.com');
+        $secretSanta->addCouple('Player', 'player@email.com', 'Couple', 'couple@email.com');
+    }
+
     public function testTwoCouples()
     {
         $secretSanta = new SecretSanta();
@@ -31,6 +63,45 @@ public function testTwoCouples()
         $this->assertSame(4 , count($combination));
     }
 
+    public function testNeverCombinationItself()
+    {
+        $secretSanta = new SecretSanta();
+        $secretSanta->addCouple('Player', 'player@email.com', 'Couple', 'couple@email.com');
+        $secretSanta->addCouple('Player2', 'player2@email.com', 'Couple2', 'couple2@email.com');
+
+        $combination = $secretSanta->play();
+        foreach ($combination as $player) {
+            $this->assertTrue($player->id() != $player->secretSanta()->id());
+        }
+    }
+
+    public function testNeverCombinationCouples()
+    {
+        $secretSanta = new SecretSanta();
+        $secretSanta->addCouple('Player', 'player@email.com', 'Couple', 'couple@email.com');
+        $secretSanta->addCouple('Player2', 'player2@email.com', 'Couple2', 'couple2@email.com');
+
+        $combination = $secretSanta->play();
+        foreach ($combination as $player) {
+            switch ($player->email()) {
+                case 'player@email.com';
+                    $this->assertTrue($player->secretSanta()->email() != 'couple@email.com');
+                    break;
+                case 'couple@email.com';
+                    $this->assertTrue($player->secretSanta()->email() != 'player@email.com');
+                    break;
+                case 'player2@email.com';
+                    $this->assertTrue($player->secretSanta()->email() != 'couple2@email.com');
+                    break;
+                case 'couple2@email.com';
+                    $this->assertTrue($player->secretSanta()->email() != 'player2@email.com');
+                    break;
+                default:
+                    $this->assertTrue(false);
+            }
+        }
+    }
+
     public function testTwoCouplesAndPlayer()
     {
         $secretSanta = new SecretSanta();
@@ -89,4 +160,84 @@ public function testTenCouplesAndTenPlayers()
 
         $this->assertSame(30 , count($combination));
     }
+
+    public function testTenCouples()
+    {
+        $secretSanta = new SecretSanta();
+
+        $secretSanta->addCouple('Player3', 'player3@email.com', 'Couple3', 'couple3@email.com');
+        $secretSanta->addCouple('Player4', 'player4@email.com', 'Couple4', 'couple4@email.com');
+        $secretSanta->addCouple('Player5', 'player5@email.com', 'Couple5', 'couple5@email.com');
+        $secretSanta->addCouple('Player6', 'player6@email.com', 'Couple6', 'couple6@email.com');
+        $secretSanta->addCouple('Player13', 'player13@email.com', 'Couple13', 'couple13@email.com');
+        $secretSanta->addCouple('Player14', 'player14@email.com', 'Couple14', 'couple14@email.com');
+        $secretSanta->addCouple('Player15', 'player15@email.com', 'Couple15', 'couple15@email.com');
+        $secretSanta->addCouple('Player16', 'player16@email.com', 'Couple16', 'couple16@email.com');
+        $secretSanta->addCouple('Player19', 'player19@email.com', 'Couple19', 'couple19@email.com');
+        $secretSanta->addCouple('Player20', 'player20@email.com', 'Couple20', 'couple20@email.com');
+
+        $combination = $secretSanta->play();
+
+        $this->assertSame(20 , count($combination));
+    }
+
+    public function testFiftyCouples()
+    {
+        $secretSanta = new SecretSanta();
+
+        $secretSanta->addCouple('Player', 'player@email.com', 'Couple', 'couple@email.com');
+        $secretSanta->addCouple('Player2', 'player2@email.com', 'Couple2', 'couple2@email.com');
+        $secretSanta->addCouple('Player3', 'player3@email.com', 'Couple3', 'couple3@email.com');
+        $secretSanta->addCouple('Player4', 'player4@email.com', 'Couple4', 'couple4@email.com');
+        $secretSanta->addCouple('Player5', 'player5@email.com', 'Couple5', 'couple5@email.com');
+        $secretSanta->addCouple('Player6', 'player6@email.com', 'Couple6', 'couple6@email.com');
+        $secretSanta->addCouple('Player7', 'player7@email.com', 'Couple7', 'couple7@email.com');
+        $secretSanta->addCouple('Player8', 'player8@email.com', 'Couple8', 'couple8@email.com');
+        $secretSanta->addCouple('Player9', 'player9@email.com', 'Couple9', 'couple9@email.com');
+        $secretSanta->addCouple('Player10', 'player10@email.com', 'Couple10', 'couple10@email.com');
+        $secretSanta->addCouple('Player11', 'player11@email.com', 'Couple11', 'couple11@email.com');
+        $secretSanta->addCouple('Player12', 'player12@email.com', 'Couple12', 'couple12@email.com');
+        $secretSanta->addCouple('Player13', 'player13@email.com', 'Couple13', 'couple13@email.com');
+        $secretSanta->addCouple('Player14', 'player14@email.com', 'Couple14', 'couple14@email.com');
+        $secretSanta->addCouple('Player15', 'player15@email.com', 'Couple15', 'couple15@email.com');
+        $secretSanta->addCouple('Player16', 'player16@email.com', 'Couple16', 'couple16@email.com');
+        $secretSanta->addCouple('Player17', 'player17@email.com', 'Couple17', 'couple17@email.com');
+        $secretSanta->addCouple('Player18', 'player18@email.com', 'Couple18', 'couple18@email.com');
+        $secretSanta->addCouple('Player19', 'player19@email.com', 'Couple19', 'couple19@email.com');
+        $secretSanta->addCouple('Player20', 'player20@email.com', 'Couple20', 'couple20@email.com');
+        $secretSanta->addCouple('Player21', 'player21@email.com', 'Couple21', 'couple21@email.com');
+        $secretSanta->addCouple('Player22', 'player22@email.com', 'Couple22', 'couple22@email.com');
+        $secretSanta->addCouple('Player23', 'player23@email.com', 'Couple23', 'couple23@email.com');
+        $secretSanta->addCouple('Player24', 'player24@email.com', 'Couple24', 'couple24@email.com');
+        $secretSanta->addCouple('Player25', 'player25@email.com', 'Couple25', 'couple25@email.com');
+        $secretSanta->addCouple('Player26', 'player26@email.com', 'Couple26', 'couple26@email.com');
+        $secretSanta->addCouple('Player27', 'player27@email.com', 'Couple27', 'couple27@email.com');
+        $secretSanta->addCouple('Player28', 'player28@email.com', 'Couple28', 'couple28@email.com');
+        $secretSanta->addCouple('Player29', 'player29@email.com', 'Couple29', 'couple29@email.com');
+        $secretSanta->addCouple('Player30', 'player30@email.com', 'Couple30', 'couple30@email.com');
+        $secretSanta->addCouple('Player31', 'player31@email.com', 'Couple31', 'couple31@email.com');
+        $secretSanta->addCouple('Player32', 'player32@email.com', 'Couple32', 'couple32@email.com');
+        $secretSanta->addCouple('Player33', 'player33@email.com', 'Couple33', 'couple33@email.com');
+        $secretSanta->addCouple('Player34', 'player34@email.com', 'Couple34', 'couple34@email.com');
+        $secretSanta->addCouple('Player35', 'player35@email.com', 'Couple35', 'couple35@email.com');
+        $secretSanta->addCouple('Player36', 'player36@email.com', 'Couple36', 'couple36@email.com');
+        $secretSanta->addCouple('Player37', 'player37@email.com', 'Couple37', 'couple37@email.com');
+        $secretSanta->addCouple('Player38', 'player38@email.com', 'Couple38', 'couple38@email.com');
+        $secretSanta->addCouple('Player39', 'player39@email.com', 'Couple39', 'couple39@email.com');
+        $secretSanta->addCouple('Player40', 'player40@email.com', 'Couple40', 'couple40@email.com');
+        $secretSanta->addCouple('Player41', 'player41@email.com', 'Couple41', 'couple41@email.com');
+        $secretSanta->addCouple('Player42', 'player42@email.com', 'Couple42', 'couple42@email.com');
+        $secretSanta->addCouple('Player43', 'player43@email.com', 'Couple43', 'couple43@email.com');
+        $secretSanta->addCouple('Player44', 'player44@email.com', 'Couple44', 'couple44@email.com');
+        $secretSanta->addCouple('Player45', 'player45@email.com', 'Couple45', 'couple45@email.com');
+        $secretSanta->addCouple('Player46', 'player46@email.com', 'Couple46', 'couple46@email.com');
+        $secretSanta->addCouple('Player47', 'player47@email.com', 'Couple47', 'couple47@email.com');
+        $secretSanta->addCouple('Player48', 'player48@email.com', 'Couple48', 'couple48@email.com');
+        $secretSanta->addCouple('Player49', 'player49@email.com', 'Couple49', 'couple49@email.com');
+        $secretSanta->addCouple('Player50', 'player50@email.com', 'Couple50', 'couple50@email.com');
+
+        $combination = $secretSanta->play();
+
+        $this->assertSame(100 , count($combination));
+    }
 }