Game to Game Itemization
I often hear streamers/pros say they will get X item because the other team has Y champion, but I'm not really getting the logic behind these choices. Obviously I understand stuff like if the other team has 4 AD with a support Lux, then stack armor, or if they have an AP top and Jg, then get plenty MR. Also I get the obvious counters, like Zhonyas or QSS vs. Zed and such. But sometimes I hear somebody say stuff like "I'm building Sunfire b/c I'm against Riven". Point being that I don't understand why "Riven" is so important here and other cases like this.
Can anybody explain to me more in-depth about counter-itemizing?