This was an item guide for 13.20. As 14.4, builds are still being put to the test. Threats chapter has not been fully updated, but find pleasure reading.
Rune, summenor and skill order is up to date, and are expected to remain same over time.
I hold 400% more experience in TOP than MID, my preference being ~70% top, ~20% bot and remaining in mid "hopefully". I am old and my reactions are unlike what they once were, but relying on experience goes a long way, and should be valued more than mechanics. I consider myself a very casual player, that find beauty in details.
Any of these minor advices won't matter if you are not well experienced with Yasuo already.

Very niche items are not showcased in the item section, e.g. Boots of Swiftness, and will instead be mentioned in the sections of guide chapters, threats, synergies, match ups and so on.

Bruiser Extremely common top lane matchup. They collect a lot of AD and health. Yasuo is quite vulnerable to these and often need to play by their rules. Common tricks include opting for Cut Down and Blade of the Ruined King.

Cheesers: These bruisers look for an early all in to set you behind early on, this tactic is often hard to respond to and need to be answered proactively, most often referred to as cheese.

- Darius, daddy D. There are two essential components to this lane and both of these are under Darius control. Firstly is his Ghost, once he uses the three minute long cooldown spell, it screams his intention to go for the kill. You should make a choice yourself to use a summenor spell too. If he grabbed you, you need to flash his Q, if he is far and chasing you could insted ghost. Secondly is his grab, E Apprehend, this skill is too valuble as it provides around three free stacks of his passive. Landing this skill on you should spell your death. Sometimes flash isn't enough as the slow is very powerful thereafter. Yasuo must prioritize baiting this ability out. One of Yasuo's greatest tricks can be used to bait it out and that is approaching him with charged Q. Casting tornado simuntaneously as he grabs you denies him free stacks and you can retreat or fight, is your choice. Like any bruiser or tank it is preferable to deal as much free damage as possible on Darius before commiting yourself. Beware Sterak's Gage, this shield is known to expire before being broken. This provides seconds enough to grant Darius the stacks needed.

- Olaf. Olaf is dangerous straight away due to his continuous axe throw Undertow that he then picks up. Consider unlocking Wind Wall as early as level 2 to delete the axe and putting it to the full cooldown of 9 seconds, as of patch 14.4, this lowers a part of Olaf's dps and more importantly allows you to move. Trades with Olaf without his axe can work, but remain very deadly. Your main technique against all in:ing bruisers is the face tornado, you approach Olaf with stacked Q Steel Tempest, attack him a few times and when you're done you toss the tornado. If you need to play more defensively, don't do this far into the lane and preferably near your tower, this match up is one of them and these types of champion uses Ghost. Ragnarok is infamously annoying for many champions that rely on crowd control in their rotations, Yasuo in top is definitely one of them. You need to create space against Olaf once he unleashes his rage and ghost. You can go Ghost yourself to make it easier, but Ignite is preferable due to the inbuilt healing in the champion's design. Mainly though to create space you need to dash into the wave, even if it puts you on the wrong side of the lane. Deleting his axe becomes crucial as it would allow him to close the distance. As of patch 14.4, Ragnarok has a 3 second duration and can be extended continuously up to 2.5 seconds, after main duration has lapsed, if he is allowed to strike a champion. With slight gold lead, this champion is not very hard to kill. Althouh him killing you is just as likely if you are sloppy.

- Sett. Grasp of the Undying, Bone Plating.

- Renekton. Grasp of the Undying, Bone Plating.

Stabilizers: Stabilizers uphold the strategy to keep the lane neutral to lead into their eventual powerspike, may it be first back or first completed item. Before that they have the intention and sometimes also many tools to neutralize your aggression and keep the lane stable, most commonly a disengage of sorts.

+ Camille. In lane Yasuo needs to attempt to deal as much free damage as possible without taking any yourself. HP becomes the true resource of the lane since both parties healing are miniscule. The better poker will take lane priority or easily even all in the other. Try to create lead early as Yasuo is tributed the tools to do so here. Main trading tools Camille uses is her passive Adaptive Defenses, try to output your cards before it triggers and once it does, you simply create space or even disengage entirely. This champion never outscales you if you maintain good economy.

- Nasus, the DOG. Wither will be used as disengage tool, and later when fully maxed as a disabler at every stage of the game, nullifying your presence and impact. This monster doesn't neccessary outscale you, but his kit counters you heavily post a certain stage, as said before wither nullifies you as a threat, if you failed to shut him down, do you best to play around him, either by avoiding him and not match him in the side lane or buy items that creates space between you, most prominently Boots of Swiftness, Iceborn Gauntlet, and Dead Man's Plate or a combination of a few. Still in the end, without any way to inflict damage to pressure Nasus holding him in the side is futile as the towers will not hold against him.

Dance Partners: Dance Partner should keep a balanced lane where both participants should have similar agency. They look to fight back, and also wait for their own item powerspike, doing parts of multiple categories. Essentially the remaining skill match ups that couldn't find their own category.

+ Aatrox, chosen Aatrix. Like Riven, you should track his cooldown, but instead this is not to avoid losing a trade or lane, but for Yasuo to find opportunity to Win trades. It is important to win trades early on as Aatrox gain strength quickly with each level. Never get struck by Aatrox enhanced auto attack, and wait for him to last hit with it. It is truly the only guaranteed damage Aatrox can inflict. Push slowly into him, which fishes out Aatrox to last hit with his abilities. Outside of this you should use precognition and to still dodge his abilities as the CC and damage potence of Aatrox outmatches yours. Running Ignite into him is both helpful in lane, and incredibly valuable later on before buying Mortal Reminder. Having the option to forgo this item, due to having ignite, is a benefit. This only happens if Aatrox is not doing well, if he is then mortal reminder is usually always a requirement, as the uptime of grevious wounds is unmatched. Rush Berserker's Greaves, into Blade of the Ruined King, then Zeal should make this match up quite easy. Additionally buying Chain Vest and completeing it into Iceborn Gauntlet is a great second legendary item. Late game his survivability is problematic, so Mortal Reminder is highly advised. You might be able to 1v1 him safely, but keeping him alive for too long will hurt your teamfights. Still he is not to be underestimated as he technically can fight you even late game, even if it is Yasuo favored.

- Riven. Fleet Footwork, Zeal.

- Jax. Stormrazor!!, Berserker's Greaves.

Precision Precision tree is an essential tree for Yasuo and Lethal Tempo is the core component to enhance Yasuo's strength in the early game. As of patch 14.4, this has been nerfed, but still proves to be the best strategy.

++ Best, most value at the right time Using Yasuo's early strength to the fullest, enables consistent snowballing - highly important for Yasuo. The rune gets guaranteed value, in contrast to its counterparts Last Stand and Cut Down. This rune loses usefulness beyond early effectiveness as the numbers cannot compete with said counterparts..

++ Most Value Cut Down easily contributes the highest numbers when enemies draft 1 or 2 high health targets. In top a lot of high health champions are found. Yasuo's early source of health should only be Overgrowth and HP scaling rune. As of Season 14 Yasuo, not only in top lane, benefits more from the incorporation of survivalabity from one or up to two tank items than marksman items alone composing the build for Yasuo. In the event you opt for zero tank items this rune should be considered against both bruisers and tanks. From tests Last Stand remains between 100-800 extra damage for a 35 minute game. While Cut Down contributes between 5000 to 7000 of damage in both games, whether Yasuo lost lane or not. Games tested was against enemy Sion top (35minutes). This ends up equating to ~10% of final damage dealt each game. Of course the gap difference will lower if the circumstance changes, for example when against an opponent that can pressure Yasuo harder that can get Yasuo low on HP to trigger Last Stand for longer time.

+ Default This rune outperforms Coup de Grace at all stages, but it cannot be applied unless you are low. Being able to apply value right away is the real of strength of Yasuo, which Last Stand is unable to do. When Yasuo is hard winning or losing, Yasuo won't have any use of this rune. This rune remains a good default rune as both counterparts Coup de Grace and Cut Down need to be used in a specific ways. Last Stand start to show its strength in the all commit fights with Irelia, Yone. Although with finesse Coup de Grace is better.

DOMINATION Domination, a typical secondary page. It aid snowball and contribute strength in the early lane.

+ Ease in Trade Taste of Blood compensates for aggressive playstyle - basically mend the damage taken from minions when trading aggressively. Helps in top, but more useful in Bot- and Mid lane as Bone Plating makes this obsolete in top lane.

+ Profit Nudger Treasure Hunter is a strong filler to get great powerspikes, for instance Berserker's Greaves. It's truly only great with a coordinated premade support when playing bot lane with catch and dive champions like Thresh, and Alistar respectively. Remember in Bot lane a double kill yield 120 gold, whereas 50 gold in the solo lane!

RESOLVE Resolve, a typical secondary page. It aids beginners more than domination, or more importantly reduces the efficiency of hard matchups.

++ Break between Trades When Bone Plating is up, like for anyone else. It is time to head bash! Bone plating is preferably taken against dangerous burst oriented melee match ups to save you from Pantheon, Renekton! Bone plating can also be chosen to hard win trades early on against Riven, Fiora. Bone plating prevents no damage initially and required a sequence of attacks on to you to have an effect. Although as of 14.6, this rune won't trigger until your shield is gone, making the use of this rune much, much better, might not have worked in the past, but certainly now.

- Prime Filler Rune Not as necessary as Bone Plating becomes in many melee match ups, but always solid filler that typically scales better, not always. Take it if you put no thought into your strategy. That's okay, but then you generally conform to a more passive playstyle.

- Mitigate Harass Second Wind is a solid defensive rune against low damage, DoT's and especially ranged. Basically opponents that can trigger it frequently without outtrading the positive return from the exchange. It works similarly to Doran's Shield, which is why it makes for a good combination. Although Yasuo with high confidence can usually utilize bushes and Steel Tempest to attain lane priority against any match up level 1, or against weak champions ( Kayle, Cassiopeia) E start and dash on top of them

+ For Synergies On it's own, it's not really great, it can enhance your shield from flow Way of the Wanderer, and from purchases like Immortal Shieldbow. It truly shines with an enchanter on the team. Then it will scale real well, playing bot even better as the benefits are attributed right away, e.g. Ivern.

+ Prime Source of Tenacity Unflinching is a highly attractive rune since it is the most relevant source of tenacity. Although it should be unecessary if the enemy CC comprises of avoidable or blockable spells.