Yasuo Runes explained
There's one set of runes for Yasuo on patch 13.21 that is the clear favorite for LoL players and pros alike. The best Yasuo rune paths on the position 
Adc are 
Precision as the primary path and 
Resolve as the secondary path with a pick rate of 90%. Besides picking runes on Yasuo you should learn how to play Yasuo and if you are interested in pro matches take a look on how a pro builds Yasuo. If you want to discuss 
Yasuo then you should visit the champion subreddit.
Yasuo runes from primary path
Precision improves attack and sustained damage on Yasuo 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 Yasuo. This keystone rune gives Yasuo a great head start in team fights and allows to put out more damage in that time window. Other primary runes on Yasuo are 
Triumph, 
Legend: Alacrity and 
Last Stand.
Triumph restores on Yasuo a part of missing health and award bonus gold, if a champion is killed. Legend: Alacrity grants additional attack speed to Yasuo. With Last Stand you deal more damage while you are at low health.
Yasuo runes from secondary path
When it comes to your secondary path, most Yasuo players prefer to go with Resolve. Resolve empowers the survivability of Yasuo and increases the tankiness. On the Resolve path, the best runes for Yasuo are 
Second Wind and 
Revitalize.
Second Wind powers up your sustainablity in lane by healing after taking damage from an enemy champion. Revitalize inceases heals and shields you distribute or receive.
FAQ for Yasuo Runes
Which is the best keystone rune on Yasuo?
The best keystone rune on Yasuo is Lethal Tempo. This Yasuo runes setup is then referred as Yasuo Lethal Tempo.
What runes does Yasuo use?
Runes from the paths Precision and Resolve are the most used runes on Yasuo. For the exact pick rates of Yasuo runes used, you have to study the rune distribution presented.