diff --git a/js/chess.js b/js/chess.js
index be6a664..d4a5f52 100644
--- a/js/chess.js
+++ b/js/chess.js
@@ -70,7 +70,7 @@ function boardGet(board, where, side){
 }
 
 function boardPut(board, where, side, piece){
-   side = isDark(side) ? 'dark' : 'light';
+   side = normalizeSide(side);
    var column = 'abcdefgh'.indexOf(where[0]);
    var row = Number(where[1]) - 1;
    var data = board[side][row];
@@ -368,11 +368,11 @@ function renderHistory(board) {
          const took = move.took ? 'x' : '';
          result += SHY + '*' + piece + took + move.to;
       } else {
-         if (n > 0 || move.side === 'dark') {
+         if (n > 0 || isDark(move.side)) {
             result += ' ';
          }
 
-         if (move.side === 'light') {
+         if (isLight(move.side)) {
             ++n;
             result += String(n) + '.' + NBSP;
          }
@@ -380,7 +380,7 @@ function renderHistory(board) {
          if (move.pass) {
             result += '...';
          } else if (move.alongside) {
-            if (move.side === 'light') {
+            if (isLight(move.side)) {
                result += move.type.toUpperCase() + move.alongside.toUpperCase() + move.from + move.to;
             } else {
                result += move.alongside.toUpperCase() + move.type.toUpperCase() + move.from + move.to;
@@ -471,7 +471,7 @@ function renderBoard(board){
       }
    }
 
-   var clss = board.player === 'light' ? '.cb-lt-piece' : '.cb-dk-piece';
+   var clss = isLight(board.player) ? '.cb-lt-piece' : '.cb-dk-piece';
 
    if (board.phantom) {
       var where = board.phantom.from;
@@ -497,9 +497,9 @@ function renderBoard(board){
 
    var msg = '';
    if (board.move && board.move.took === 'k') {
-      msg = (board.move.side[0] === 'd' ? 'Dark' : 'Light') + ' player won!';
+      msg = (isDark(board.move.side) ? 'Dark' : 'Light') + ' player won!';
    } else {
-      msg = (board.player[0] === 'd' ? 'Dark' : 'Light') + " player's move";
+      msg = (isDark(board.player) ? 'Dark' : 'Light') + " player's move";
    }
    $('#cb_message').text(msg);
 
@@ -615,9 +615,9 @@ function switchGameId(newId){
             /* ignore partial moves and undo/redo */
             if (!board.phantom && !board.subsequent) {
                if (board.move && board.move.took === 'k') {
-                  notify((board.move.side[0] === 'd' ? 'Dark' : 'Light') + ' player won!');
+                  notify((isDark(board.move.side) ? 'Dark' : 'Light') + ' player won!');
                } else {
-                  notify((board.player[0] === 'd' ? 'Dark' : 'Light') + ' player\'s turn');
+                  notify((isDark(board.player) ? 'Dark' : 'Light') + ' player\'s turn');
                }
                $('#cb_board').data('skip_notify', d.board);
             }