Apparently Essence Reaver has an issue that doesnt give full CDR when having a cloak of agility let alone a brawlers glove. Brawlers glove gives 3% cdr for idk what reason and cloak gives 10% cdr which makes literally 0 sense.
Brawlers should give 6.66 aka 7%
http://na.leagueoflegends.com/en/news/game-updates/patch/patch-524-notes#patch-Essence-Reaver
The math below is a little wonky, but here’s the gist of it - at 20% crit (from say, Zeal), you’ll get 10% cooldown reduction. At 30% crit (from Zeal’s upgrades), you’ll get the same 20% cooldown reduction you’re used to.
Bonus cooldown reduction per point of critical strike chance from other sources now increases as critical strike chance from other sources increases (ie. no longer a flat value)
They don't provide the formula for how the numbers work together, but from the numbers they do provide it should be evident that you get more CDR per crit with more crit chance.
20% crit (2/3 the max needed) => 10% CDR (1/2 the max gained) 30% crit (max needed) => 20% CDR (max gained)
Notice how to get the first 10% CDR it took 20% crit, but the last 10% CDR only took 10% more crit.
http://leagueoflegends.wikia.com/wiki/Essence_Reaver The wiki has a formula which is: CDR = CRIT × (CRIT/10 + 1) ÷ 6 This formula works for the values Riot gave in the patch notes and for the 3% you got for brawlers glove. Do keep in mind that the values displayed in game are often rounded; 3.33 would get rounded to just 3.
