Quite often, it is easier to notice the aberrations caused by certain patches, than the sinking of certain champions . Other than their most loyal OTPs, very few people notice that they are slowly disappearing to the bottom of the ranks of the most mediocre characters. This can be done slowly, as the game evolves, due to outdated mechanics , or much more quickly and the alarm bells have to be sounded. This is the case of Cho Gath , whose winrate was very expensive during this pre-season.
From OK tier to trash tier
The Black Terror was a pretty good champion in previous patches. His winrate was just over 51% , which was more than enough to make him a more than viable, but not entirely OP, option. Only the last modifications put him a big blow behind the neck, making him lose nearly 4.5% of winrate. Today Cho Gath is at 46.95% winrate at platinum + ranks , which is enough to put him in the category of champions in difficulty, according to the criteria of Riot Games which estimates that a champion is bad from 48 % win rate.
An item problem?
Only Cho Gath was not directly nerfed by Riot Games. Its fall in the tier list cannot therefore be explained by a decision by the publisher of League of Legends. The reason must therefore be sought elsewhere. His choice of mythic evolved with the pre-season , where players tend to favor the SteelHeart . This drop in winrate corresponds to the change in build of Cho Gath, which would rather give reason to people saying that the SteelHeart is not such a good item . Although the item theoretically provides an infinite amount of HP , so it would make sense for it to work well with a champion whose power of ultimate is partly dependent on their maximum health.
Only when you look at the statistics, it appears that staying on the classic build with the Frosting Gauntlet is a better idea, allowing you to gain 2% winrate . The problem with this data is the low number of games with this item at platinum + ranks; which prevents analyzing if it is really a better option, or if it is a build adapted to specific match ups. If we take into account the data on the whole ladder (thus including the ranks below Platinum), the stats do not move too much for the Freezing Gauntlet with a better sample of games (over 6000), but the HeartSteel takes a leap forward and also increases to 48% winrate, even becoming a little better than the Gauntlet (at 0.01%).
Maybe we should look elsewhere for the reason for this drop in winrate, by looking at the buffs of certain bruiser items like the Ravenous Hydra which will be nerfed in 12.23. Maybe Cho Gath is just having a bad time with the overall balance of the game, and once the formula is tweaked, he will move up the rankings . To be continued, but what remains certain is that even taking into account the lowest ranks (where the champion is supposed to be better, because relatively easy to play/build, which means that it is difficult totally int with him), his winrate has still dropped significantly, making him the champion who lost the most winrate over the last patch.