anchor.diff:    });
   
     $deleteGameLink.on( "click", function() {
  -    initializeNewGame();
  +    if ( $( this ).text() === 'Undo' ) {
  +      currentGame = getCookie( "oldGame" );
  +      currentGameData = getCookie( "oldGameData" );
  +      initializeFromCookie();
  +      $( this ).text( 'New game' );
  +    } else {
  +      setCookie( "oldGame", currentGame );
  +      setCookie( "oldGameData", currentGameData );
  +      initializeNewGame();
  +      $( this ).text( 'Undo' );
  +    }
     });
   
     $showDatePicker.on( "dp.change", function( e ) {
  
positive.code:     var modified = ( currentGame["play_type"] !== $playTypeSelect.val() );
      currentGame["play_type"] = $playTypeSelect.val();
      updateCookies( modified );
    }
  
    function initializeNewGame( date ) {
  
negative.code:     getScoresFromCookie();
      populateBoard();
    } else if ( currentGame ) {
      initializeFromCookie();
    } else {
      initializeNewGame();
      getScoresFromCookie();
  