Twitch Runes explained
There's one set of runes for Twitch on patch 15.4 that is the clear favorite for LoL players and pros alike. The best Twitch rune paths on the position 
Adc are 
Precision as the primary path and 
Sorcery as the secondary path with a pick rate of 52%. Besides picking runes on Twitch you should learn how to play Twitch and if you are interested in pro matches take a look on how a pro builds Twitch. If you want to discuss 
Twitch then you should visit the champion subreddit.
Twitch runes from primary path
Precision improves attack and sustained damage on Twitch troughout the match. Most of high elo players – and our LoL pros in the the major regions – have agreed that 
Lethal Tempo is the best keystone rune to run on Twitch. This keystone rune gives Twitch a great head start in team fights and allows to put out more damage in that time window. Other primary runes on Twitch are 
Presence of Mind, 
Legend: Alacrity and 
Cut Down.
Presence of Mind helps Twitch with the mana problems by restoring missing mana, if a champion is killed. Legend: Alacrity grants additional attack speed to Twitch. If the enemy team consists of multiple tanks, then the rune Cut Down is the best choice.
Twitch runes from secondary path
When it comes to your secondary path, most Twitch players prefer to go with Sorcery. Sorcery empoweres abilities of Twitch and increases the available champion resources. On the Sorcery path, the best runes for Twitch are 
Axiom Arcanist and 
Gathering Storm.
Axiom Arcanist grants you a shield, as soon as Twitch gets hurt by alot of magic damage. This rune will help you alot to survive against ability power champions with a lot of burst damage. Gathering Storm increases your late game power.
FAQ for Twitch Runes
Which is the best keystone rune on Twitch?
The best keystone rune on Twitch is Lethal Tempo. This Twitch runes setup is then referred as Twitch Lethal Tempo.
What runes does Twitch use?
Runes from the paths Precision and Sorcery are the most used runes on Twitch. For the exact pick rates of Twitch runes used, you have to study the rune distribution presented.