php - 获胜的机会

I'm currently making a little script. Whenever the user hits submit in this script, he/she should have X% chance of winning. Currently I have this:

function winningChance() {
  $won = "you lost";
  $ret = 2 * rand(1, 50);
  if($ret == 100) {
    $won = "you won!";  
  }
  return $won;
}


echo winningChance();

Although this is not very advanced, how can I do so I can set the percentage chance of winning?

function winningChance(int $percentage): string
{
    if ($percentage < 0 || $percentage > 100) {
        throw new \Exception('Invalid percentage');
    }

    return rand(1, 100) <= $percentage ? 'won' : 'lost';
}

echo "You've " . winningChance(50) . '!';