Confusion in validation due to classes in Kernel file: Laravel 5.2.37

I have a request class that validates if the input has only alphabets. This is working fine no problem.

Validation works because Kernel.php file looks like below.

protected $middleware = [
    \Illuminate\Foundation\Http\Middleware\CheckForMaintenanceMode::class,
    \Illuminate\Session\Middleware\StartSession::class,
    \Illuminate\View\Middleware\ShareErrorsFromSession::class,
    \App\Http\Middleware\VerifyCsrfToken::class,
];

/**
 * The application's route middleware groups.
 *
 * @var array
 */
protected $middlewareGroups = [
    'web' => [
        \App\Http\Middleware\EncryptCookies::class,
        \Illuminate\Cookie\Middleware\AddQueuedCookiesToResponse::class,
    ],

    'api' => [
        'throttle:60,1',
    ],
];

Validation DOES NOT work if Kernel .php file looks like below.

protected $middleware = [
    \Illuminate\Foundation\Http\Middleware\CheckForMaintenanceMode::class,
];

/**
 * The application's route middleware groups.
 *
 * @var array
 */
protected $middlewareGroups = [
    'web' => [
        \App\Http\Middleware\EncryptCookies::class,
        \Illuminate\Cookie\Middleware\AddQueuedCookiesToResponse::class,
        \Illuminate\Session\Middleware\StartSession::class,
        \Illuminate\View\Middleware\ShareErrorsFromSession::class,
        \App\Http\Middleware\VerifyCsrfToken::class,
    ],

    'api' => [
        'throttle:60,1',
    ],
];

My very simple route file is below

Route::group(['middleware' => ['web']], function () {
    Route::get('/Sports-Types',              'SportsTypeController@index');
    Route::get('/Create-Sports-Type',        'SportsTypeController@create');
    Route::post('/SaveSportsType',           'SportsTypeController@store');
    Route::put('/UpdateSportsType',          'SportsTypeController@update');
    Route::get('/SportsType/{SportsTypeID}', 'SportsTypeController@edit');
});

What's the confusion and Question

As we can see above, we have Route group with web Middleware. Why the validation is not working when Web middleware does not have following class in Kernel file.

\Illuminate\Session\Middleware\StartSession::class,
\Illuminate\View\Middleware\ShareErrorsFromSession::class,
\App\Http\Middleware\VerifyCsrfToken::class,

Can somebody guide me in right direction?

via Chebli Mohamed