Minimax Tic Tac Toe Javascript game wont play intelligently

Question

Good Afternoon,

can someone please help me figure out why my Tic Tac Toe javascript game wont play intelligently...meaning that it shouldn't let me win. I've spent hours on this and still cant figure it out. Here is the link to my project: http://codepen.io/tbraden30/pen/WrorjE Thank you so much!

"use-strict"
$(document).ready(function() {
  var gameBoard = [' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' '],
    humanPlayer = 'X',
    EMPTY = ' ',
    computerPlayer = 'O',
    currentPlayer = 'computer',
    choice;

  function buildBoard(board) {
    $('td').each(function(index) {
      $(this).text(board[index]);
    });
  }

  function makeMove(board, symbol, move) {
    board[move] = symbol;
  }

  function checkWin(board, player) {
    return ((board[0] == player && board[1] == player && board[2] == player) || (board[3] == player && board[4] == player && board[5] == player) || (board[6] == player && board[7] == player && board[8] == player) || (board[0] == player && board[3] == player && board[6] == player) || (board[1] == player && board[4] == player && board[7] == player) || (board[0] == player && board[4] == player && board[8] == player) || (board[2] == player && board[4] == player && board[6] == player) || (board[2] == player && board[5] == player && board[8] == player));
  }

  function boardSpaceOpen(board, move) {
    return board[move] == EMPTY;
  }

  function boardIsFull(board) {
    for (var i = 0; i < board.length; i++) {
      if (boardSpaceOpen(board, i)) {
        return false;
      }
    }
    return true;
  }

  function resetBoard() {
    gameBoard = [' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' '];
    buildBoard(gameBoard);
    currentPlayer = 'computer';
    computerPlay();
  }



  function computerPlay() {
    var moves = getOpenSpaces(gameBoard);
    var move = moves[0];
    var score = -10000;
    for (var i = 0; i < moves.length; i++) {
      var newBoard = gameBoard.slice();
      newBoard[moves[i]] = computerPlayer;

      if (checkWin(computerPlayer, newBoard)) {
        move = moves[i];
        break;
      }
      var newScore = minimax(humanPlayer, newBoard);
      if (newScore > score) {
        score = newScore;
        choice = moves[i];
      }
    }
    makeMove(gameBoard, computerPlayer, move);
    buildBoard(gameBoard);

    if (checkWin(gameBoard, computerPlayer)) {
      alert('computer Wins!!');
      resetBoard();
    } else if (boardIsFull(gameBoard)) {
      alert('DRAW!!');
      resetBoard();
    } else {
      currentPlayer = 'human';
    }
  }

  function getOpenSpaces(board) {
    var emptySpaces = [];
    for (var i = 0; i < board.length; i++) {
      if (boardSpaceOpen(board, i)) {
        emptySpaces.push(i);
      }
    }
    return emptySpaces;
  }

  function getOpponentOf(player) {
    return currentPlayer == 'computer' ? 'human' : 'computer';
  }

  function minimax(board, player) {
    if (checkWin(board, humanPlayer)) {
      return -100
    }
    if (checkWin(board, computerPlayer)) {
      return 100
    }
    if (boardIsFull(board)) {
      return 0;
    }

    var availableMoves = getOpenSpaces(board);
    var scores = availableMoves.map(function(move){
      var newBoard = board.slice();
      newBoard[move] = player; 
      return minimax(getOpponentOf(currentPlayer), newBoard);
    });

    if(currentPlayer == 'computer'){
      return Math.max.apply(null,scores);
    }
    else{
      return Math.min.apply(null,scores)
    }
  }



  $('#reset').on('click', function() {
    resetBoard();
  });

  $('.piece').on('click', function() {
   humanPlayer = this.id;
   computerPlayer = humanPlayer == 'X' ? 'O' : 'X';
   computerPlay();
  });

  $('td').on('click', function() {
    if (currentPlayer == 'human') {
      var move = this.id;
      if (boardSpaceOpen(gameBoard, move)) {
        makeMove(gameBoard, humanPlayer, move);
        buildBoard(gameBoard);

        if (checkWin(gameBoard, humanPlayer)) {
          alert('You Won!!');
          resetBoard();
        } else if (boardIsFull(gameBoard)) {
          alert('DRAW!!');
          resetBoard();
        } else {
          currentPlayer = 'computer';
          computerPlay();
        }
      }
    }
  });

});