Улучшить код крестиков-ноликов

class Game { 
  constructor() { 
    this.game = document.getElementById("game") 
    this.gameBlock = document.getElementsByClassName("game_block") 
    this.winnerDOM = document.getElementById("win") 
    this.btnReset = document.getElementById("btn-reset") 
    this.cloneGameBlock = new Array(this.gameBlock.length) 
    this.current = 0 
  } 
 
  calculateWinner(squares) { 
    const lines = [ 
      [0, 1, 2], 
      [3, 4, 5], 
      [6, 7, 8], 
      [0, 3, 6], 
      [1, 4, 7], 
      [2, 5, 8], 
      [0, 4, 8], 
      [2, 4, 6] 
    ] 
 
    for (let i = 0; i < lines.length; i++) { 
      const [a, b, c] = lines[i] 
      if ( 
        squares[a] && 
        squares[a] === squares[b] && 
        squares[a] === squares[c] 
      ) { 
        return squares[a] 
      } 
    } 
 
    return null 
  } 
 
  cloneAnArray() { 
    for (let i = 0; i < this.cloneGameBlock.length; i++) { 
      this.cloneGameBlock[i] = this.gameBlock[i].innerHTML 
    } 
  } 
 
  winnerDom() { 
    if (this.calculateWinner(this.cloneGameBlock)) { 
      this.winnerDOM.style.display = "block" 
      this.winnerDOM.innerHTML = `Победитель: ${this.calculateWinner(this.cloneGameBlock)}` 
    } 
  } 
 
  resetGame() { 
    for (let i = 0; i < this.gameBlock.length; i++) { 
      this.gameBlock[i].innerHTML = "" 
      this.cloneGameBlock[i] = "" 
    } 
    this.winnerDOM.innerHTML = "" 
    this.current = 0 
  } 
 
  addCymeriad(index) { 
    if (!this.calculateWinner(this.cloneGameBlock)) { 
      if (!this.gameBlock[index].innerHTML) { 
        this.current++ 
          this.current % 2 ? 
          (this.gameBlock[index].innerHTML = "X") : 
          (this.gameBlock[index].innerHTML = "0") 
      } 
      this.cloneAnArray() 
    } 
    this.winnerDom() 
  } 
} 
 
const game = new Game() 
 
const { 
  gameBlock, 
  btnReset 
} = game 
 
for (let i = 0; i < gameBlock.length; i++) { 
  gameBlock[i].addEventListener("click", () => game.addCymeriad(i)) 
} 
 
btnReset.addEventListener("click", () => game.resetGame())

#game { 
  width: 120px; 
  height: 120px; 
  margin: 30px auto; 
  outline: 1px solid black; 
  display: flex; 
  flex-wrap: wrap; 
} 
 
.game_block { 
  width: 40px; 
  height: 40px; 
  outline: 1px solid black; 
  transition: .4s; 
  text-align: center; 
  line-height: 40px; 
  font-size: 44px; 
} 
 
.game_block:hover { 
  background: rgb(241, 238, 238); 
  cursor: pointer; 
} 
 
#win { 
  display: none; 
  text-align: center; 
} 
 
.flex { 
  display: flex; 
} 
 
.flex-center { 
  justify-content: center; 
}

<div id="game"> 
  <div class="game_block"></div> 
  <div class="game_block"></div> 
  <div class="game_block"></div> 
  <div class="game_block"></div> 
  <div class="game_block"></div> 
  <div class="game_block"></div> 
  <div class="game_block"></div> 
  <div class="game_block"></div> 
  <div class="game_block"></div> 
</div> 
<h2 id='win'></h2> 
<div class="flex flex-center"> 
  <button id='btn-reset'>Начать заново</button> 
</div>