A lost ball should not fly off again before the player is ready. We add a state variable, and resetBall() now puts
the ball on the paddle, standing still, in the 'serve' state.
```js
let state // 'serve', 'playing', 'won' or 'lost'
function resetBall() {
state = 'serve'
ball = { x: paddle.x + PADDLE_W / 2, y: PADDLE_Y - BALL_R, vx: 0, vy: 0 }
}
```
What it means
state holds which phase the game is in; the comment lists every value it will have.
resetBall() now sets the state to 'serve' and puts the ball on the middle of the paddle with no velocity.
Your turn
Under let bricks write let state with its comment.
In resetBall, add state = 'serve' and change the ball line as shown.