From php artisan tinker I called $val->passes() and get the following error

[3] > $val = $player->getValidator($aPlayer);
// object(Illuminate\Validation\Validator)(
//   'container' => object(Illuminate\Foundation\Application)(
//
//   )
// )
[4] > $val->passes();
PHP Fatal error:  Uncaught exception 'BadMethodCallException' with message 'Method [validateBoolean] does not exist.' in /vagrant/laravel/vendor/laravel/framework/src/Illuminate/Validation/Validator.php:2225

When I remove the boolean validation rule...

[3] > $val = $player->getValidator($aPlayer);
// object(Illuminate\Validation\Validator)(
//   'container' => object(Illuminate\Foundation\Application)(
//
//   )
// )
[4] > $val->passes();
// true
[5] > exit();