diff --git a/src/Variant/AbstractPiece.php b/src/Variant/AbstractPiece.php
index 644af09ef..466f22227 100644
--- a/src/Variant/AbstractPiece.php
+++ b/src/Variant/AbstractPiece.php
@@ -10,7 +10,6 @@
 use Chess\Variant\Classical\PGN\AN\Castle;
 use Chess\Variant\Classical\PGN\AN\Color;
 use Chess\Variant\Classical\PGN\AN\Piece;
-use Chess\Variant\Classical\PGN\AN\Square;
 use Chess\Variant\Classical\Rule\CastlingRule;
 
 abstract class AbstractPiece
@@ -29,13 +28,6 @@ abstract class AbstractPiece
      */
     public string $sq;
 
-    /**
-     * Square.
-     *
-     * @var \Chess\Variant\Classical\PGN\AN\Square
-     */
-    public Square $square;
-
     /**
      * Identifier.
      *
@@ -67,14 +59,12 @@ abstract class AbstractPiece
     /**
      * @param string $color
      * @param string $sq
-     * @param \Chess\Variant\Classical\PGN\AN\Square $square
      * @param string $id
      */
-    public function __construct(string $color, string $sq, Square $square, string $id)
+    public function __construct(string $color, string $sq, string $id)
     {
         $this->color = $color;
         $this->sq = $sq;
-        $this->square = $square;
         $this->id = $id;
     }
 
diff --git a/src/Variant/Capablanca/Piece/A.php b/src/Variant/Capablanca/Piece/A.php
index e0faeaca9..59e06c409 100644
--- a/src/Variant/Capablanca/Piece/A.php
+++ b/src/Variant/Capablanca/Piece/A.php
@@ -14,7 +14,7 @@ class A extends AbstractLinePiece
 
     public function __construct(string $color, string $sq, Square $square)
     {
-        parent::__construct($color, $sq, $square, Piece::A);
+        parent::__construct($color, $sq, Piece::A);
 
         $this->mobility = [
             ...(new B($color, $sq, $square))->mobility,
diff --git a/src/Variant/Capablanca/Piece/C.php b/src/Variant/Capablanca/Piece/C.php
index d956f0de4..89eda5bc4 100644
--- a/src/Variant/Capablanca/Piece/C.php
+++ b/src/Variant/Capablanca/Piece/C.php
@@ -15,7 +15,7 @@ class C extends AbstractLinePiece
 
     public function __construct(string $color, string $sq, Square $square)
     {
-        parent::__construct($color, $sq, $square, Piece::C);
+        parent::__construct($color, $sq, Piece::C);
 
         $this->mobility = [
             ...(new R($color, $sq, $square, RType::R))->mobility,
diff --git a/src/Variant/Classical/Piece/B.php b/src/Variant/Classical/Piece/B.php
index ce65621fa..3397fdd81 100644
--- a/src/Variant/Classical/Piece/B.php
+++ b/src/Variant/Classical/Piece/B.php
@@ -10,7 +10,7 @@ class B extends AbstractLinePiece
 {
     public function __construct(string $color, string $sq, Square $square)
     {
-        parent::__construct($color, $sq, $square, Piece::B);
+        parent::__construct($color, $sq, Piece::B);
 
         $this->mobility = [
             0 => [],
@@ -21,7 +21,7 @@ public function __construct(string $color, string $sq, Square $square)
 
         $file = ord($this->file()) - 1;
         $rank = $this->rank() + 1;
-        while ($file >= 97 && $rank <= $this->square::SIZE['ranks']) {
+        while ($file >= 97 && $rank <= $square::SIZE['ranks']) {
             $this->mobility[0][] = chr($file) . $rank;
             $file -= 1;
             $rank += 1;
@@ -29,7 +29,7 @@ public function __construct(string $color, string $sq, Square $square)
 
         $file = ord($this->file()) + 1;
         $rank = $this->rank() + 1;
-        while ($file <= 97 + $this->square::SIZE['files'] - 1 && $rank <= $this->square::SIZE['ranks']) {
+        while ($file <= 97 + $square::SIZE['files'] - 1 && $rank <= $square::SIZE['ranks']) {
             $this->mobility[1][]  = chr($file) . $rank;
             $file += 1;
             $rank += 1;
@@ -45,7 +45,7 @@ public function __construct(string $color, string $sq, Square $square)
 
         $file = ord($this->file()) + 1;
         $rank = $this->rank() - 1;
-        while ($file <= 97 + $this->square::SIZE['files'] - 1 && $rank >= 1) {
+        while ($file <= 97 + $square::SIZE['files'] - 1 && $rank >= 1) {
             $this->mobility[3][] = chr($file) . $rank;
             $file += 1;
             $rank -= 1;
diff --git a/src/Variant/Classical/Piece/K.php b/src/Variant/Classical/Piece/K.php
index 5b16550c9..d2d24be8f 100644
--- a/src/Variant/Classical/Piece/K.php
+++ b/src/Variant/Classical/Piece/K.php
@@ -13,12 +13,12 @@ class K extends AbstractPiece
 {
     public function __construct(string $color, string $sq, Square $square)
     {
-        parent::__construct($color, $sq, $square, Piece::K);
+        parent::__construct($color, $sq, Piece::K);
 
         $this->mobility = [];
 
         $rank = $this->rank() + 1;
-        if ($rank <= $this->square::SIZE['ranks']) {
+        if ($rank <= $square::SIZE['ranks']) {
             $this->mobility[] = $this->file() . $rank;
         }
 
@@ -33,19 +33,19 @@ public function __construct(string $color, string $sq, Square $square)
         }
 
         $file = ord($this->file()) + 1;
-        if ($file <= 97 + $this->square::SIZE['files'] - 1) {
+        if ($file <= 97 + $square::SIZE['files'] - 1) {
             $this->mobility[] = chr($file) . $this->rank();
         }
 
         $file = ord($this->file()) - 1;
         $rank = $this->rank() + 1;
-        if ($file >= 97 && $rank <= $this->square::SIZE['ranks']) {
+        if ($file >= 97 && $rank <= $square::SIZE['ranks']) {
             $this->mobility[] = chr($file) . $rank;
         }
 
         $file = ord($this->file()) + 1;
         $rank = $this->rank() + 1;
-        if ($file <= 97 + $this->square::SIZE['files'] - 1 && $rank <= $this->square::SIZE['ranks']) {
+        if ($file <= 97 + $square::SIZE['files'] - 1 && $rank <= $square::SIZE['ranks']) {
             $this->mobility[] = chr($file) . $rank;
         }
 
@@ -57,7 +57,7 @@ public function __construct(string $color, string $sq, Square $square)
 
         $file = ord($this->file()) + 1;
         $rank = $this->rank() - 1;
-        if ($file <= 97 + $this->square::SIZE['files'] - 1 && $rank >= 1) {
+        if ($file <= 97 + $square::SIZE['files'] - 1 && $rank >= 1) {
             $this->mobility[] = chr($file) . $rank;
         }
     }
@@ -169,7 +169,7 @@ public function castle(string $rookType): bool
                 new K(
                     $this->color,
                     $this->board->castlingRule->rule[$this->color][Piece::K][rtrim($this->move['pgn'], '+')]['to'],
-                    $this->square
+                    $this->board->square
                 )
              );
             $this->board->detach($rook);
@@ -177,7 +177,7 @@ public function castle(string $rookType): bool
                 new R(
                     $rook->color,
                     $this->board->castlingRule->rule[$this->color][Piece::R][rtrim($this->move['pgn'], '+')]['to'],
-                    $this->square,
+                    $this->board->square,
                     $rook->type
                 )
             );
diff --git a/src/Variant/Classical/Piece/N.php b/src/Variant/Classical/Piece/N.php
index 1f346e548..451dae517 100644
--- a/src/Variant/Classical/Piece/N.php
+++ b/src/Variant/Classical/Piece/N.php
@@ -11,14 +11,14 @@ class N extends AbstractPiece
 {
     public function __construct(string $color, string $sq, Square $square)
     {
-        parent::__construct($color, $sq, $square, Piece::N);
+        parent::__construct($color, $sq, Piece::N);
 
         $this->mobility = [];
 
         try {
             $file = chr(ord($this->file()) - 1);
             $rank = $this->rank() + 2;
-            if ($this->square->validate($file . $rank)) {
+            if ($square->validate($file . $rank)) {
                 $this->mobility[] = $file . $rank;
             }
         } catch (UnknownNotationException $e) {
@@ -27,7 +27,7 @@ public function __construct(string $color, string $sq, Square $square)
         try {
             $file = chr(ord($this->file()) - 2);
             $rank = $this->rank() + 1;
-            if ($this->square->validate($file . $rank)) {
+            if ($square->validate($file . $rank)) {
                 $this->mobility[] = $file . $rank;
             }
         } catch (UnknownNotationException $e) {
@@ -36,7 +36,7 @@ public function __construct(string $color, string $sq, Square $square)
         try {
             $file = chr(ord($this->file()) - 2);
             $rank = $this->rank() - 1;
-            if ($this->square->validate($file . $rank)) {
+            if ($square->validate($file . $rank)) {
                 $this->mobility[] = $file . $rank;
             }
         } catch (UnknownNotationException $e) {
@@ -45,7 +45,7 @@ public function __construct(string $color, string $sq, Square $square)
         try {
             $file = chr(ord($this->file()) - 1);
             $rank = $this->rank() - 2;
-            if ($this->square->validate($file . $rank)) {
+            if ($square->validate($file . $rank)) {
                 $this->mobility[] = $file . $rank;
             }
         } catch (UnknownNotationException $e) {
@@ -54,7 +54,7 @@ public function __construct(string $color, string $sq, Square $square)
         try {
             $file = chr(ord($this->file()) + 1);
             $rank = $this->rank() - 2;
-            if ($this->square->validate($file . $rank)) {
+            if ($square->validate($file . $rank)) {
                 $this->mobility[] = $file . $rank;
             }
         } catch (UnknownNotationException $e) {
@@ -63,7 +63,7 @@ public function __construct(string $color, string $sq, Square $square)
         try {
             $file = chr(ord($this->file()) + 2);
             $rank = $this->rank() - 1;
-            if ($this->square->validate($file . $rank)) {
+            if ($square->validate($file . $rank)) {
                 $this->mobility[] = $file . $rank;
             }
         } catch (UnknownNotationException $e) {
@@ -72,7 +72,7 @@ public function __construct(string $color, string $sq, Square $square)
         try {
             $file = chr(ord($this->file()) + 2);
             $rank = $this->rank() + 1;
-            if ($this->square->validate($file . $rank)) {
+            if ($square->validate($file . $rank)) {
                 $this->mobility[] = $file . $rank;
             }
         } catch (UnknownNotationException $e) {
@@ -81,7 +81,7 @@ public function __construct(string $color, string $sq, Square $square)
         try {
             $file = chr(ord($this->file()) + 1);
             $rank = $this->rank() + 2;
-            if ($this->square->validate($file . $rank)) {
+            if ($square->validate($file . $rank)) {
                 $this->mobility[] = $file . $rank;
             }
         } catch (UnknownNotationException $e) {
diff --git a/src/Variant/Classical/Piece/P.php b/src/Variant/Classical/Piece/P.php
index 7edd3b857..8c6da2e8d 100644
--- a/src/Variant/Classical/Piece/P.php
+++ b/src/Variant/Classical/Piece/P.php
@@ -17,16 +17,16 @@ class P extends AbstractPiece
 
     public function __construct(string $color, string $sq, Square $square)
     {
-        parent::__construct($color, $sq, $square, Piece::P);
+        parent::__construct($color, $sq, Piece::P);
 
         $this->ranks = $this->color === Color::W
             ? [
                 'start' => 2,
                 'next' => $this->rank() + 1,
-                'end' => $this->square::SIZE['ranks'],
+                'end' => $square::SIZE['ranks'],
             ]
             : [
-                'start' => $this->square::SIZE['ranks'] - 1,
+                'start' => $square::SIZE['ranks'] - 1,
                 'next' => $this->rank() - 1,
                 'end' => 1,
             ];
@@ -36,29 +36,29 @@ public function __construct(string $color, string $sq, Square $square)
         $this->mobility = [];
 
         // next rank
-        if ($this->ranks['next'] <= $this->square::SIZE['ranks']) {
+        if ($this->ranks['next'] <= $square::SIZE['ranks']) {
             $this->mobility[] = $this->file() . $this->ranks['next'];
         }
 
         // two square advance
         if ($this->rank() === 2 && $this->ranks['start'] == 2) {
             $this->mobility[] = $this->file() . ($this->ranks['start'] + 2);
-        } elseif ($this->rank() === $this->square::SIZE['ranks'] - 1 &&
-            $this->ranks['start'] == $this->square::SIZE['ranks'] - 1
+        } elseif ($this->rank() === $square::SIZE['ranks'] - 1 &&
+            $this->ranks['start'] == $square::SIZE['ranks'] - 1
         ) {
             $this->mobility[] = $this->file() . ($this->ranks['start'] - 2);
         }
 
         // capture square
         $file = ord($this->file()) - 1;
-        if ($file >= 97 && $this->ranks['next'] <= $this->square::SIZE['ranks']) {
+        if ($file >= 97 && $this->ranks['next'] <= $square::SIZE['ranks']) {
             $this->captureSqs[] = chr($file) . $this->ranks['next'];
         }
 
         // capture square
         $file = ord($this->file()) + 1;
-        if ($file <= 97 + $this->square::SIZE['files'] - 1 &&
-            $this->ranks['next'] <= $this->square::SIZE['ranks']
+        if ($file <= 97 + $square::SIZE['files'] - 1 &&
+            $this->ranks['next'] <= $square::SIZE['ranks']
         ) {
             $this->captureSqs[] = chr($file) . $this->ranks['next'];
         }
@@ -89,7 +89,7 @@ public function moveSqs(): array
         $end = end($history);
         if ($end && $end['id'] === Piece::P && $end['color'] === $this->oppColor()) {
             if ($this->color === Color::W) {
-                if ($this->rank() === $this->square::SIZE['ranks'] - 3) {
+                if ($this->rank() === $this->board->square::SIZE['ranks'] - 3) {
                     $captureSq = $end['to'][0] . ($this->rank() + 1);
                     if (in_array($captureSq, $this->captureSqs)) {
                         $this->enPassantSq = $captureSq;
diff --git a/src/Variant/Classical/Piece/Q.php b/src/Variant/Classical/Piece/Q.php
index 319199ae1..788e46480 100644
--- a/src/Variant/Classical/Piece/Q.php
+++ b/src/Variant/Classical/Piece/Q.php
@@ -11,7 +11,7 @@ class Q extends AbstractLinePiece
 {
     public function __construct(string $color, string $sq, Square $square)
     {
-        parent::__construct($color, $sq, $square, Piece::Q);
+        parent::__construct($color, $sq, Piece::Q);
 
         $this->mobility = [
             ...(new R($color, $sq, $square, RType::R))->mobility,
diff --git a/src/Variant/Classical/Piece/R.php b/src/Variant/Classical/Piece/R.php
index b35a4da4c..2d02ea0dc 100644
--- a/src/Variant/Classical/Piece/R.php
+++ b/src/Variant/Classical/Piece/R.php
@@ -12,7 +12,7 @@ class R extends AbstractLinePiece
 
     public function __construct(string $color, string $sq, Square $square, string $type)
     {
-        parent::__construct($color, $sq, $square, Piece::R);
+        parent::__construct($color, $sq, Piece::R);
 
         $this->type = $type;
 
@@ -23,7 +23,7 @@ public function __construct(string $color, string $sq, Square $square, string $t
             3 => [],
         ];
 
-        for ($i = $this->rank() + 1; $i <= $this->square::SIZE['ranks']; $i++) {
+        for ($i = $this->rank() + 1; $i <= $square::SIZE['ranks']; $i++) {
             $this->mobility[0][] = $this->file() . $i;
         }
 
@@ -35,7 +35,7 @@ public function __construct(string $color, string $sq, Square $square, string $t
             $this->mobility[2][] = chr($i) . $this->rank();
         }
 
-        for ($i = ord($this->file()) + 1; $i <= 97 + $this->square::SIZE['files'] - 1; $i++) {
+        for ($i = ord($this->file()) + 1; $i <= 97 + $square::SIZE['files'] - 1; $i++) {
             $this->mobility[3][] = chr($i) . $this->rank();
         }
     }
diff --git a/src/Variant/Losing/Piece/M.php b/src/Variant/Losing/Piece/M.php
index 36bff12e3..ede2aae17 100644
--- a/src/Variant/Losing/Piece/M.php
+++ b/src/Variant/Losing/Piece/M.php
@@ -11,14 +11,14 @@ class M extends AbstractPiece
 {
     public function __construct(string $color, string $sq, Square $square)
     {
-        parent::__construct($color, $sq, $square, Piece::M);
+        parent::__construct($color, $sq, Piece::M);
 
         $this->mobility = [];
 
         try {
             $file = $this->sq[0];
             $rank = $this->rank() + 1;
-            if ($this->square->validate($file . $rank)) {
+            if ($square->validate($file . $rank)) {
                 $this->mobility[] = $file . $rank;
             }
         } catch (UnknownNotationException $e) {
@@ -27,7 +27,7 @@ public function __construct(string $color, string $sq, Square $square)
         try {
             $file = $this->sq[0];
             $rank = $this->rank() - 1;
-            if ($this->square->validate($file . $rank)) {
+            if ($square->validate($file . $rank)) {
                 $this->mobility[] = $file . $rank;
             }
         } catch (UnknownNotationException $e) {
@@ -36,7 +36,7 @@ public function __construct(string $color, string $sq, Square $square)
         try {
             $file = chr(ord($this->sq[0]) - 1);
             $rank = $this->rank();
-            if ($this->square->validate($file . $rank)) {
+            if ($square->validate($file . $rank)) {
                 $this->mobility[] = $file . $rank;
             }
         } catch (UnknownNotationException $e) {
@@ -45,7 +45,7 @@ public function __construct(string $color, string $sq, Square $square)
         try {
             $file = chr(ord($this->sq[0]) + 1);
             $rank = $this->rank();
-            if ($this->square->validate($file . $rank)) {
+            if ($square->validate($file . $rank)) {
                 $this->mobility[] = $file . $rank;
             }
         } catch (UnknownNotationException $e) {
@@ -54,7 +54,7 @@ public function __construct(string $color, string $sq, Square $square)
         try {
             $file = chr(ord($this->sq[0]) - 1);
             $rank = $this->rank() + 1;
-            if ($this->square->validate($file . $rank)) {
+            if ($square->validate($file . $rank)) {
                 $this->mobility[] = $file . $rank;
             }
         } catch (UnknownNotationException $e) {
@@ -63,7 +63,7 @@ public function __construct(string $color, string $sq, Square $square)
         try {
             $file = chr(ord($this->sq[0]) + 1);
             $rank = $this->rank() + 1;
-            if ($this->square->validate($file . $rank)) {
+            if ($square->validate($file . $rank)) {
                 $this->mobility[] = $file . $rank;
             }
         } catch (UnknownNotationException $e) {
@@ -72,7 +72,7 @@ public function __construct(string $color, string $sq, Square $square)
         try {
             $file = chr(ord($this->sq[0]) - 1);
             $rank = $this->rank() - 1;
-            if ($this->square->validate($file . $rank)) {
+            if ($square->validate($file . $rank)) {
                 $this->mobility[] = $file . $rank;
             }
         } catch (UnknownNotationException $e) {
@@ -81,7 +81,7 @@ public function __construct(string $color, string $sq, Square $square)
         try {
             $file = chr(ord($this->sq[0]) + 1);
             $rank = $this->rank() - 1;
-            if ($this->square->validate($file . $rank)) {
+            if ($square->validate($file . $rank)) {
                 $this->mobility[] = $file . $rank;
             }
         } catch (UnknownNotationException $e) {