Naafiri Runes explained
There's one set of runes for Naafiri on patch 13.24 that is the clear favorite for LoL players and pros alike. The best Naafiri rune paths on the position 
Mid are 
Inspiration as the primary path and Sorcery as the secondary path with a pick rate of 48%. Besides picking runes on Naafiri you should learn how to play Naafiri and if you are interested in pro matches take a look on how a pro builds Naafiri.
Naafiri runes from primary path
Inspiration opens creative opportunities on Naafiri troughout the match. Most of high elo players – and our LoL pros in the the major regions – have agreed that First Strike is the best keystone rune to run on 
Naafiri. Other primary runes on Naafiri are Magical Footwear, Biscuit Delivery and Cosmic Insight.
Magical Footwear allows Naafiri to focus on those essential core items without the need to spend the additional 300 gold on boots. Biscuit Delivery is a great rune for laning as it gives additional health and mana, which can help in more aggressive lanes. Cosmic Insight grants summoner spell and item haste.
Naafiri runes from secondary path
When it comes to your secondary path, most Naafiri players prefer to go with Sorcery. Sorcery empoweres abilities of Naafiri and increases the available champion resources. On the Sorcery path, the best runes for Naafiri are Scorch and Absolute Focus.
Scorch increases your control in the early game. Absolute Focus grants additional damage while Naafiri is alomst full health.
FAQ for Naafiri Runes
Which is the best keystone rune on Naafiri?
The best keystone rune on Naafiri is First Strike. This Naafiri runes setup is then referred as Naafiri First Strike.
What runes does Naafiri use?
Runes from the paths Inspiration and Sorcery are the most used runes on Naafiri. For the exact pick rates of Naafiri runes used, you have to study the rune distribution presented.