Yasuo's winrate spike is because of a bugfix, not the Tank build
Now, I understand this is a post about Yasuo, by a Yasuo main, so before you downvote, hear me out.
We've been discussing over at the /r/YasuoMains subreddit what caused his winrate to spike into what it is now. Ultimately, we don't like his current situation. Let's be real, you wouldn't like it if your main had a 40% ban rate in all elos.
Frozen Force (or what you may alternatively know as Tank Yasuo) has been around for a few patches, coined by ArKaDaTa, an EUW Challenger Yasuo OTP. Before the most recent patch, Yasuo has had a relatively unproblematic winrate up until this patch, 6.17. There were no changes made to Yasuo, except for a tiny fix to a bug that would make Yasuo unable to autoattack after casting his ult if it was a critical strike. So, with this evidence, we can take Tank Yasuo out of the reason why his winrate spiked.
In the video above, it demonstrates that Yasuo can cancel his autoattack animation by casting R, which causes slightly higher, but noticable, damage per second. So now, instead of the usual e>q>aa>r>aa combo, it's now e>q>aa>aa>r>aa, a total of 3 autoattacks that all apply critical strike damage if the Yasuo has 100% crit, as well as adds 6 more Fervor of Battle stacks, which give him bonus damage on his autoattacks. His ult also gives him 50% armor penetration, which is added on top of damage from Fervor stacks, Q damage, and critical strike damage. This "bug" was nonexistant in Patch 6.16.
Tank Yasuo can be a minor factor in how high his winrate is, but isn't why it spiked. The build (agreeably) forgives him for any mistakes he might make, and yes, makes him much harder to deal with. However, the bug itself is the reason why his winrate spiked.
I wanted to shed some light on this before Riot hits Yasuo in the wrong spot, so he isn't unnecessarily gutted.
Thanks for reading.