Naafiri Runes explained
There's one set of runes for Naafiri on patch 15.4 that is the clear favorite for LoL players and pros alike. The best Naafiri rune paths on the position 
Mid are 
Sorcery as the primary path and Resolve as the secondary path with a pick rate of 36%. 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
Sorcery empoweres abilities of Naafiri and increases the available champion resources. Most of high elo players – and our LoL pros in the the major regions – have agreed that Hail of Blades is the best keystone rune to run on 
Naafiri. This keystone rune helps you to win short damage trades in your lane by increasing your attackspeed at the beginning of a fight. Other primary runes on Naafiri are Manaflow Band, Absolute Focus and Scorch.
This is usually followed up by taking Manaflow Band for additional mana and mana regenaration. Absolute Focus grants additional damage while Naafiri is alomst full health. Scorch increases your control in the early game.
Naafiri runes from secondary path
When it comes to your secondary path, most Naafiri players prefer to go with Resolve. Resolve empowers the survivability of Naafiri and increases the tankiness. On the Resolve path, the best runes for Naafiri are Overgrowth and Second Wind.
Overgrowth increases your maximum amount of health. Second Wind powers up your sustainablity in lane by healing after taking damage from an enemy champion.
FAQ for Naafiri Runes
Which is the best keystone rune on Naafiri?
The best keystone rune on Naafiri is Hail of Blades. This Naafiri runes setup is then referred as Naafiri Hail of Blades.
What runes does Naafiri use?
Runes from the paths Sorcery and Resolve are the most used runes on Naafiri. For the exact pick rates of Naafiri runes used, you have to study the rune distribution presented.