diff --git a/README.md b/README.md
new file mode 100644
index 0000000..0fdcf66
--- /dev/null
+++ b/README.md
@@ -0,0 +1,121 @@
+# Glicko2 rating system
+
+[![License](https://img.shields.io/github/license/laxity7/glicko2.svg)](https://github.com/laxity7/glicko2/blob/master/LICENSE)
+[![Latest Stable Version](https://img.shields.io/packagist/v/laxity7/glicko2.svg)](https://packagist.org/packages/laxity7/glicko2)
+[![Total Downloads](https://img.shields.io/packagist/dt/laxity7/glicko2.svg)](https://packagist.org/packages/laxity7/glicko2)
+
+A PHP implementation of [Glicko2 rating system](http://www.glicko.net/glicko.html)
+
+The Glicko2 rating system is a popular algorithm used to calculate the skill levels of players in various competitive
+games. It takes into account both the player's performance and the strength of their opponents, providing more accurate
+and up-to-date ratings compared to traditional methods like Elo. The system uses a logarithmic function that adjusts a
+player's rating based on the outcome of their matches, with higher-skilled players having a greater impact on their
+opponent's ratings. Glicko2 also employs a confidence interval and a smoothing parameter to further refine the accuracy
+and stability of the rankings.
+
+The Glicko2 rating system is an advanced Elo system that was used in Mark Zuckerberg's infamous Facemash website
+
+Supports PHP versions 7.4 and 8.*
+
+## Installation
+
+For installation via Composer run:
+
+`composer require laxity7/glicko2`
+
+## Usage
+
+For example, you have a table in the database with the following fields:
+
+```php
+use laxity7\glicko2\Player;
+use App\UserRating;
+
+class UserRating
+{
+    public int $user_id;
+    public float $rating;
+    public float $rating_deviation;
+    public float $rating_volatility;
+}
+
+class Repository
+{
+    public function getUserRating(int $userId)
+    {
+        $userRating = $this->findInDbFromId($userId);
+        if (!$userRating) {
+            $userRating = $this->createUserRating($userId);
+        }
+        return $userRating;
+    }
+    
+    public function createUserRating(int $userId)
+    {
+        $player = new Player();
+        $userRating = new UserRating();
+        $userRating->user_id = $userId;
+        $userRating->rating = $player->getRating();
+        $userRating->rating_deviation = $player->getRatingDeviation();
+        $userRating->rating_volatility = $player->getRatingVolatility();
+    
+        $this->saveToDb($userRating);
+        
+        return $userRating;
+    }
+    
+    public function updateRating(int $userId, Player $player)
+    {
+        $userRating = $this->getUserRating($userId);
+        $userRating->rating = $player->getRating();
+        $userRating->rating_deviation = $player->getRatingDeviation();
+        $userRating->rating_volatility = $player->getRatingVolatility();
+
+        $this->saveToDb($userRating);
+    }
+}
+```
+
+Ok, preparation completed, lets play
+
+```php
+use laxity7\glicko2\MatchGame;
+use laxity7\glicko2\MatchCollection;
+use laxity7\glicko2\Player;
+
+$repository = new Repository();
+
+$userRating1 = $repository->getUserRating(1);
+$userRating2 = $repository->getUserRating(2);
+
+$player1 = new Player($userRating1->rating, $userRating1->rating_deviation, $userRating1->rating_volatility);
+$player2 = new Player($userRating2->rating, $userRating2->rating_deviation, $userRating2->rating_volatility);
+//$player2 = new Player(); available defaults for new player
+
+// match chain
+$match1 = new MatchGame($player1, $player2, 1, 0);
+$match1->calculate(); // The calculation method does not return anything, it only calculates and changes the rating of players
+
+$match2 = new MatchGame($player1, $player2, 3, 2);
+$match2->calculate();
+
+// or match collection
+$matchCollection = new MatchCollection();
+$matchCollection->addMatch(new MatchGame($player1, $player2, 1, 0));
+$matchCollection->addMatch(new MatchGame($player1, $player2, 3, 2));
+$matchCollection->calculate();
+
+// just get a new ratings
+$newPlayer1Rating = $player1->getRating();
+$newPlayer2Rating = $player2->getRating();
+
+// for example, save to the database
+$repository->updateRating(1, $player1);
+$repository->updateRating(2, $player2);
+```
+
+## Author
+
+[Aleksandr Zelenin](https://github.com/zelenin/), e-mail: [aleksandr@zelenin.me](mailto:aleksandr@zelenin.me)
+
+[Vlad Varlamov](https://github.com/laxity7/), e-mail: [vlad@varlamov.dev](mailto:vlad@varlamov.dev)
diff --git a/composer.json b/composer.json
index 9aa6bdb..9b72e03 100644
--- a/composer.json
+++ b/composer.json
@@ -18,7 +18,7 @@
         },
         {
             "name": "Vlad Varlamov",
-            "email": "work@laxity.ru",
+            "email": "vlad@varlamov.dev",
             "role": "Developer"
         }
     ],
@@ -27,7 +27,7 @@
         "source": "https://github.com/laxity7/glicko2"
     },
     "require": {
-        "php": ">=7.1.0"
+        "php": "^7.4|^8.0"
     },
     "require-dev": {
         "phpunit/phpunit": "~5.3.0"
diff --git a/readme.md b/readme.md
deleted file mode 100644
index 56bc39e..0000000
--- a/readme.md
+++ /dev/null
@@ -1,93 +0,0 @@
-# Glicko2 rating system
-
-[![License](https://img.shields.io/github/license/laxity7/glicko2.svg)](https://github.com/laxity7/glicko2/blob/master/LICENSE)
-[![Latest Stable Version](https://img.shields.io/packagist/v/laxity7/glicko2.svg)](https://packagist.org/packages/laxity7/glicko2)
-[![Total Downloads](https://img.shields.io/packagist/dt/laxity7/glicko2.svg)](https://packagist.org/packages/laxity7/glicko2)
-
-A PHP implementation of [Glicko2 rating system](http://www.glicko.net/glicko.html)
-
-## Installation
-
-### Composer
-
-The preferred way to install this extension is through [Composer](http://getcomposer.org/).
-
-Either run
-
-```
-php composer.phar require laxity7/glicko2 "~1.0.0"
-```
-
-or add
-
-```
-"laxity7/glicko2": "~1.0.0"
-```
-
-to the require section of your ```composer.json```
-
-## Usage
-
-For ease of understanding take ActiveRecord pattern.
-
-Somewhere create object. Attribute names can be any
-
-```php
-use laxity7\glicko2\Player;
-// ...
-public function createUserRating(int $userId)
-{
-    $userRating = new UserRating();
-    $userRating->user_id = $userId;
-    $player = new Player();
-    $userRating->rating = $player->getRating();
-    $userRating->rating_deviation = $player->getRatingDeviation();
-    $userRating->rating_volatility = $player->getRatingVolatility();
-
-    $userRating->insert();
-    
-    return $userRating;
-}
-```
-
-Ok, let's play
-
-```php
-use laxity7\glicko2\Match;
-use laxity7\glicko2\MatchCollection;
-use laxity7\glicko2\Player;
-
-$player1 = new Player($userRating1->rating, $userRating1->rating_deviation, $userRating1->rating_volatility);
-$player2 = new Player($userRating2->rating, $userRating2->rating_deviation, $userRating2->rating_volatility);
-
-// match chain
-$match1 = new Match($player1, $player2, 1, 0);
-$match1->calculate();
-
-$match2 = new Match($player1, $player2, 3, 2);
-$match2->calculate();
-
-// or match collection
-$matchCollection = new MatchCollection();
-$matchCollection->addMatch(new Match($player1, $player2, 1, 0));
-$matchCollection->addMatch(new Match($player1, $player2, 3, 2));
-$matchCollection->calculate();
-
-$newPlayer1Rating = $player1->getRating();
-$newPlayer2Rating = $player2->getRating();
-
-// for example, save in DB
-
-$userRating1->rating = $player1->getRating();
-$userRating1->rating_deviation = $player1->getRatingDeviation();
-$userRating1->rating_volatility = $player1->getRatingVolatility();
-$userRating1->update();
-
-// similarly save the second player
-```
-
-## Author
-
-[Aleksandr Zelenin](https://github.com/zelenin/), e-mail: [aleksandr@zelenin.me](mailto:aleksandr@zelenin.me)
-
-[Vlad Varlamov](https://github.com/laxity7/), e-mail: [work@laxity.ru](mailto:work@laxity.ru)
diff --git a/src/BaseMatch.php b/src/BaseMatch.php
index c736efa..04a6b3d 100644
--- a/src/BaseMatch.php
+++ b/src/BaseMatch.php
@@ -4,17 +4,14 @@
 
 abstract class BaseMatch
 {
-    /** @var Glicko2 */
-    private $ratingSystem;
+    private Glicko2 $ratingSystem;
 
     /**
      * @return Glicko2
      */
     protected function getRatingSystem(): Glicko2
     {
-        if ($this->ratingSystem === null) {
-            $this->ratingSystem = new Glicko2();
-        }
+        $this->ratingSystem ??= new Glicko2();
 
         return $this->ratingSystem;
     }
@@ -22,5 +19,5 @@ protected function getRatingSystem(): Glicko2
     /**
      * Calculate match
      */
-    abstract public function calculate();
-}
\ No newline at end of file
+    abstract public function calculate(): void;
+}
diff --git a/src/CalculationResult.php b/src/CalculationResult.php
index 5d7c21a..d3ebe69 100644
--- a/src/CalculationResult.php
+++ b/src/CalculationResult.php
@@ -4,20 +4,14 @@
 
 final class CalculationResult
 {
-    /**
-     * @var float
-     */
-    private $mu;
+    /** @var float A rating μ */
+    private float $mu;
 
-    /**
-     * @var float
-     */
-    private $phi;
+    /** @var float A rating deviation φ */
+    private float $phi;
 
-    /**
-     * @var float
-     */
-    private $sigma;
+    /** @var float A rating volatility σ */
+    private float $sigma;
 
     /**
      * @param float $mu
@@ -32,7 +26,7 @@ public function __construct(float $mu, float $phi, float $sigma)
     }
 
     /**
-     * @return float
+     * @return float A rating μ
      */
     public function getMu(): float
     {
@@ -40,7 +34,7 @@ public function getMu(): float
     }
 
     /**
-     * @return float
+     * @return float A rating deviation φ
      */
     public function getPhi(): float
     {
@@ -48,7 +42,7 @@ public function getPhi(): float
     }
 
     /**
-     * @return float
+     * @return float A rating volatility σ
      */
     public function getSigma(): float
     {
diff --git a/src/Glicko2.php b/src/Glicko2.php
index 3e4dfb9..d27465a 100644
--- a/src/Glicko2.php
+++ b/src/Glicko2.php
@@ -29,10 +29,8 @@ final class Glicko2
      * results. If the application of Glicko-2 is expected to involve extremely improbable
      * collections of game outcomes, then τ should be set to a small value, even as small as,
      * say, τ = 0.2.
-     *
-     * @var float
      */
-    private $tau;
+    private float $tau;
 
     /**
      * @param float $tau
@@ -89,7 +87,7 @@ private function v(float $phiJ, float $mu, float $muJ): float
      */
     private function g(float $phiJ): float
     {
-        return 1 / sqrt(1 + 3 * pow($phiJ, 2) / pow(M_PI, 2));
+        return 1 / sqrt(1 + 3 * ($phiJ ** 2) / (M_PI ** 2));
     }
 
     /**
@@ -129,17 +127,17 @@ private function delta(float $phiJ, float $mu, float $muJ, float $score): float
      */
     private function sigmaP(float $delta, float $sigma, float $phi, float $phiJ, float $mu, float $muJ): float
     {
-        $A = $a = log(pow($sigma, 2));
+        $A = $a = log($sigma ** 2);
         $fX = function ($x, $delta, $phi, $v, $a, $tau) {
-            return ((exp($x) * (pow($delta, 2) - pow($phi, 2) - $v - exp($x))) /
-                    (2 * pow((pow($phi, 2) + $v + exp($x)), 2))) - (($x - $a) / pow($tau, 2));
+            return ((exp($x) * (($delta ** 2) - ($phi ** 2) - $v - exp($x))) /
+                    (2 * ((($phi ** 2) + $v + exp($x)) ** 2))) - (($x - $a) / ($tau ** 2));
         };
         $epsilon = 0.000001;
         $v = $this->v($phiJ, $mu, $muJ);
         $tau = $this->tau;
 
-        if (pow($delta, 2) > (pow($phi, 2) + $v)) {
-            $B = log(pow($delta, 2) - pow($phi, 2) - $v);
+        if (($delta ** 2) > (($phi ** 2) + $v)) {
+            $B = log(($delta ** 2) - ($phi ** 2) - $v);
         } else {
             $k = 1;
             while ($fX($a - $k * $tau, $delta, $phi, $v, $a, $tau) < 0) {
@@ -175,7 +173,7 @@ private function sigmaP(float $delta, float $sigma, float $phi, float $phiJ, flo
      */
     private function phiS(float $phi, float $sigmaP): float
     {
-        return sqrt(pow($phi, 2) + pow($sigmaP, 2));
+        return sqrt(($phi ** 2) + ($sigmaP ** 2));
     }
 
     /**
@@ -186,7 +184,7 @@ private function phiS(float $phi, float $sigmaP): float
      */
     private function phiP(float $phiS, float $v): float
     {
-        return 1 / sqrt(1 / pow($phiS, 2) + 1 / $v);
+        return 1 / sqrt(1 / ($phiS ** 2) + 1 / $v);
     }
 
     /**
@@ -200,6 +198,6 @@ private function phiP(float $phiS, float $v): float
      */
     private function muP(float $mu, float $muJ, float $phiP, float $phiJ, float $score): float
     {
-        return $mu + pow($phiP, 2) * $this->g($phiJ) * ($score - $this->E($mu, $muJ, $phiJ));
+        return $mu + ($phiP ** 2) * $this->g($phiJ) * ($score - $this->E($mu, $muJ, $phiJ));
     }
 }
diff --git a/src/MatchCollection.php b/src/MatchCollection.php
index d8234a5..9accb01 100644
--- a/src/MatchCollection.php
+++ b/src/MatchCollection.php
@@ -8,9 +8,9 @@
 class MatchCollection extends BaseMatch
 {
     /**
-     * @var ArrayObject|Match[]
+     * @var MatchGame[]
      */
-    private $matches;
+    private ArrayObject $matches;
 
     public function __construct()
     {
@@ -18,15 +18,15 @@ public function __construct()
     }
 
     /**
-     * @param Match $match
+     * @param MatchGame $match
      */
-    public function addMatch(Match $match): void
+    public function addMatch(MatchGame $match): void
     {
         $this->matches->append($match);
     }
 
     /**
-     * @return ArrayIterator|Match[]
+     * @return ArrayIterator|MatchGame[]
      */
     public function getMatches(): ArrayIterator
     {
diff --git a/src/Match.php b/src/MatchGame.php
similarity index 61%
rename from src/Match.php
rename to src/MatchGame.php
index 79783f2..92588fd 100644
--- a/src/Match.php
+++ b/src/MatchGame.php
@@ -2,20 +2,21 @@
 
 namespace laxity7\glicko2;
 
-class Match extends BaseMatch
+class MatchGame extends BaseMatch
 {
-    private const RESULT_WIN = 1;
+    /** The actual score for win */
+    private const RESULT_WIN = 1.0;
+    /** The actual score for draw */
     private const RESULT_DRAW = 0.5;
-    private const RESULT_LOSS = 0;
+    /** The actual score for loss */
+    private const RESULT_LOSS = 0.0;
 
-    /** @var Player */
-    private $player1;
-    /** @var Player */
-    private $player2;
-    /** @var float */
-    private $score1;
-    /** @var float */
-    private $score2;
+    private Player $player1;
+    private Player $player2;
+    /** The player1 score */
+    private float $score1;
+    /** The player2 score */
+    private float $score2;
 
     /**
      * @param Player $player1
@@ -32,7 +33,9 @@ public function __construct(Player $player1, Player $player2, float $score1, flo
     }
 
     /**
-     * @return float
+     * Get the 1st player score
+     *
+     * @return float The 1st player score (0 for a loss, 0.5 for a draw, and 1 for a win)
      */
     public function getScore(): float
     {
@@ -49,10 +52,29 @@ public function getScore(): float
                 break;
         }
 
-        return (float) $matchScore;
+        return $matchScore;
     }
 
     /**
+     * The winner of the match. Null if it's a draw.
+     *
+     * @return Player|null
+     */
+    public function getWinner(): ?Player
+    {
+        switch ($this->getScore()) {
+            case self::RESULT_WIN:
+                return $this->player1;
+            case self::RESULT_LOSS:
+                return $this->player2;
+            default:
+                return null;
+        }
+    }
+
+    /**
+     * Get the 1st player
+     *
      * @return Player
      */
     public function getPlayer1(): Player
@@ -61,6 +83,8 @@ public function getPlayer1(): Player
     }
 
     /**
+     * Get the 2nd player
+     *
      * @return Player
      */
     public function getPlayer2(): Player
@@ -69,7 +93,7 @@ public function getPlayer2(): Player
     }
 
     /**
-     * @param Match $match
+     * Calculate and change the rating of players
      */
     public function calculate(): void
     {
diff --git a/src/Player.php b/src/Player.php
index 511ab8e..4458ad3 100644
--- a/src/Player.php
+++ b/src/Player.php
@@ -4,46 +4,37 @@
 
 class Player
 {
-    protected const CONVERT = 173.7178;
-
     public const DEFAULT_RATING = 1500;
     public const DEFAULT_RATING_DEVIATION = 350;
     public const DEFAULT_RATING_VOLATILITY = 0.06;
 
+    /** @var float Scaling factor */
+    private const RATIO = 173.7178;
+
     /**
      * A rating r
-     *
-     * @var float
      */
-    private $rating;
+    private float $rating;
 
     /**
      * A rating μ
-     *
-     * @var float
      */
-    private $ratingMu;
+    private float $ratingMu;
 
     /**
      * A rating deviation RD
-     *
-     * @var float
      */
-    private $ratingDeviation;
+    private float $ratingDeviation;
 
     /**
      * A rating deviation φ
-     *
-     * @var float
      */
-    private $ratingDeviationPhi;
+    private float $ratingDeviationPhi;
 
     /**
      * A rating volatility σ
-     *
-     * @var float
      */
-    private $ratingVolatility;
+    private float $ratingVolatility;
 
     /**
      * Player constructor.
@@ -68,7 +59,7 @@ public function __construct(
     private function setRating(float $rating): void
     {
         $this->rating = $rating;
-        $this->ratingMu = ($this->rating - static::DEFAULT_RATING) / self::CONVERT;
+        $this->ratingMu = ($this->rating - static::DEFAULT_RATING) / self::RATIO;
     }
 
     /**
@@ -77,7 +68,7 @@ private function setRating(float $rating): void
     private function setRatingMu(float $mu): void
     {
         $this->ratingMu = $mu;
-        $this->rating = $this->ratingMu * self::CONVERT + static::DEFAULT_RATING;
+        $this->rating = $this->ratingMu * self::RATIO + static::DEFAULT_RATING;
     }
 
     /**
@@ -86,7 +77,7 @@ private function setRatingMu(float $mu): void
     private function setRatingDeviation(float $ratingDeviation): void
     {
         $this->ratingDeviation = $ratingDeviation;
-        $this->ratingDeviationPhi = $this->ratingDeviation / self::CONVERT;
+        $this->ratingDeviationPhi = $this->ratingDeviation / self::RATIO;
     }
 
     /**
@@ -95,7 +86,7 @@ private function setRatingDeviation(float $ratingDeviation): void
     private function setRatingDeviationPhi(float $phi): void
     {
         $this->ratingDeviationPhi = $phi;
-        $this->ratingDeviation = $this->ratingDeviationPhi * self::CONVERT;
+        $this->ratingDeviation = $this->ratingDeviationPhi * self::RATIO;
     }
 
     /**
diff --git a/tests/Glicko2Test.php b/tests/Glicko2Test.php
index 25b6d78..855278a 100644
--- a/tests/Glicko2Test.php
+++ b/tests/Glicko2Test.php
@@ -3,7 +3,7 @@
 namespace laxity7\glicko2\Test;
 
 use PHPUnit_Framework_TestCase;
-use laxity7\glicko2\Match;
+use laxity7\glicko2\MatchGame;
 use laxity7\glicko2\MatchCollection;
 use laxity7\glicko2\Player;
 
@@ -37,7 +37,7 @@ public function testCalculateMatch()
         $player1 = new Player(1500, 200, 0.06);
         $player2 = new Player(1400, 30, 0.06);
 
-        $match = new Match($player1, $player2, 1, 0);
+        $match = new MatchGame($player1, $player2, 1, 0);
         $match->calculate();
 
         $this->assertEquals(1563.564, $this->round($player1->getRating()));
@@ -57,14 +57,14 @@ public function testCalculateMatchCollection()
         $player3 = clone $player1;
         $player4 = clone $player2;
 
-        $match = new Match($player1, $player2, 1, 0);
+        $match = new MatchGame($player1, $player2, 1, 0);
         $match->calculate();
-        $match = new Match($player1, $player2, 1, 0);
+        $match = new MatchGame($player1, $player2, 1, 0);
         $match->calculate();
 
         $matchCollection = new MatchCollection();
-        $matchCollection->addMatch(new Match($player3, $player4, 1, 0));
-        $matchCollection->addMatch(new Match($player3, $player4, 1, 0));
+        $matchCollection->addMatch(new MatchGame($player3, $player4, 1, 0));
+        $matchCollection->addMatch(new MatchGame($player3, $player4, 1, 0));
         $matchCollection->calculate();
 
         $this->assertEquals($this->round($player1->getRating()), $this->round($player3->getRating()));