Routing categories, subcategories and articles with Laravel

I often see websites that have pretty URLs for categories, subcategories and articles. How do I replicate this function with Laravel?

I need to get the following routes working:

/kb/{id (numeric)}
/kb/{category}
/kb/{category}/{article} (redirects to the route immediately below, adding the id)
/kb/{category}/{article}/{id (numeric)}
/kb/{category}/{subcategory}
/kb/{category}/{subcategory}/{article} (redirects to the route immediately below, adding the id)
/kb/{category}/{subcategory}/{article}/{id (numeric)}
/kb/download/{id (numeric)}

I was also going to try and include pretty URLs for pagination, but I realised it might complicate it further to have categories and subcategories have a /page/1 part after - but, if you know how to make that work, please tell!

Currently, my code is as follows:

Route::group(['prefix' => '/kb', 'as' => 'kb::'], function () {

    Route::get('/', function() {
        echo "<h1>Index</h1>";        
    });

    Route::get('{id}', function($id = null) {
        echo "<h1>ID: $id</h1>";
    })->where('id', '0-9+');

    Route::get('download/{id}', function($id = null) {
        echo "<h1>Download ID: $id</h1>";
    })->where('id', '0-9+');

    Route::get('{category}', function($category = null) {
        echo "<h1>Category: $category</h1>";
    });
    Route::get('{category}/{article}', function($category = null, $article = null) {
        echo "<h1>Category: $category</h1>";
        echo "<h1>Article: $article</h1>";
    });
    Route::get('{category}/{article}/{id}', function($category = null, $article = null, $id = null) {
        echo "<h1>Category: $category</h1>";
        echo "<h1>Article: $article</h1>";
        echo "<h1>ID: $id</h1>";
    })->where('id', '0-9+');

    Route::get('{category}/{subcategory}', function($category = null, $subcategory = null) {
        echo "<h1>Category: $category</h1>";
        echo "<h1>SubCategory: $subcategory</h1>";
    });
    Route::get('{category}/{subcategory}/{article}', function($category = null, $subcategory = null, $article = null) {
        echo "<h1>Category: $category</h1>";
        echo "<h1>SubCategory: $subcategory</h1>";
        echo "<h1>Article: $article</h1>";
    });
    Route::get('{category}/{subcategory}/{article}/{id}', function($category = null, $subcategory = null, $article = null, $id = null) {
        echo "<h1>Category: $category</h1>";
        echo "<h1>SubCategory: $subcategory</h1>";
        echo "<h1>Article: $article</h1>";
        echo "<h1>ID: $id</h1>";
    })->where('id', '0-9+');

});

Unfortunately, this has a habit of mixing up articles and subcategories, and is a total mess. But I see websites with this structure, and even more complicated structures, and they work - what's the secret?!

It's also important to remember that two categories might have subcategories with the same name, that aren't the same subcategory, further complicating things.

EDIT: I've also just taken a look at maybe making each article be prefixed with article, like /kb/cat/article/evil/666. Still doesn't seem to work right though, irritatingly.

via Chebli Mohamed