I'm just trying to understand how some champions just go down in win rate without any noticeable changes to them or the items that they use heck in the example of Garen is extremely easy to play and his main offensive item 
go buffed a couple patches ago, he went from 52% in patch 6.14 to 48% in patch 6.20? Heck, even his matchups didn't change that much except 
Justice has fallen my friend. It must be restored.
I'm just trying to understand how some champions just go down in win rate without any noticeable changes to them or the items that they use
we must be remembering different patches. over the course of the season
nerfed multiple times
minus 100 health
minus 10 armor, minus 100 health
minus 15 mr minus 100 health, increased ad. ad nerfed later. (the slightly cheaper price wasnt a straight buff to the item)
tradeoff. minus 50 health, + 10% cdr.
increased price (i dont buy it personally, but people still do and it affects his winrate)these are all items garen buys.
now add that together in a 4 to 6 item build. this is a good 400 hp to 500 hp less than at the start of the season. this is also a double nerf in case he picks up steraks and lost him another 200 shield hp in fights.
on top of that, ranged top laners became meta, and league of rylais started to become a thing.
carries got buffed and beat him early, while outscaling him mid/lategame.
the season 6 resolve tree is massively weaker than the season 5 defensive mastery tree, which also buffed every single carry who opts into ferocity or cunning in comparison to fighters who only synergize with resolve.
People pick him into riven. Riven got massive buffs
special mention to 
who also buys a lot of the same items and used to run 
as a core item. which also got nerfed pretty hard.
would be in the same world of shit, if they didnt fix a bug with his pull early on in the season, that didnt allow him to interrupt dashes with the ability, and his winrate shot up by almost 4%. it turned out as a pretty significant buff.
so basically this acted as some compensation which only caused his winrate to drop to 50% until now.
this items current state because of its high ap is why, it is not just Garen as other melee's are also suffering as well.
4% drop in winrate?
I suppose it's because art requires a certain cruelty.
