changed code -> You can now win, winner is announced, you can still play if the game is won tho.

code.js

@@ -15,6 +15,10 @@ let rowMax;
 let selectedPiece;
 let turnTotal = 0;
 let turnPlayer;
+let piecesX;
+let piecesO;
+let gameOver = false;
+let winner;
 let somethingIsSelected = false;
 
 for(let i = 0; i < 64; i++){
@@ -86,6 +90,7 @@ function selectField(field){
             somethingIsSelected = false;
         }
         advanceTurn();
+        checkWinCondition();
     }
 }
 function validMovesPlayer1(field){
@@ -275,4 +280,31 @@ function movePiece(field, selectedPiece){
     } else {
         return selectedPiece.piece;
     }
+}
+function checkWinCondition(){
+    piecesX = 0;
+    piecesO = 0;
+    for(let i = 0; i < 64; i++){
+        fieldId = i.toString();
+        if(document.getElementById("field"+fieldId).piece === 1){
+            piecesX++;
+        } else if(document.getElementById("field"+fieldId).piece === 11){
+            piecesX += 2;
+        } else if(document.getElementById("field"+fieldId).piece === 2){
+            piecesO++;
+        } else if(document.getElementById("field"+fieldId).piece === 22){
+            piecesO += 2;
+        }
+    }
+    if(piecesX >= (2 * piecesO)){
+        gameOver = true;
+        winner = 1;
+        document.getElementById("turnTotal").innerText = "Game Over!";
+        document.getElementById("turnPlayer").innerText = "X Won!";
+    } else if (piecesO >= (2 * piecesX)){
+        gameOver = true;
+        winner = 2;
+        document.getElementById("turnTotal").innerText = "Game Over!";
+        document.getElementById("turnPlayer").innerText = "O Won!";
+    }
 }