LoL: Ability Haste will replace Cooldown Reduction in the 2021 preseason
Cooldown Reduction
WTF IS ABILITY HASTE - NEW COOL DOWN REDUCTION EXPLAINED LEAGUE OF LEGENDS SEASON 11 CDR vs HASTE - YouTube
SEASON 10* 95% COOLDOWN REDUCTION! New 1 Second Ult CD Trick - League of Legends - YouTube
A guide to Stat Shards—League's new runes feature for the 2019 season - Dot Esports
Lowest possible Ultimate cooldown for every champion in League of Legends - GameRiv
I made a chart to convert CDR to Ability Haste : r/leagueoflegends
LoL Math - Soraka: Ability Power vs. Cooldown Reduction - YouTube
A Beginner's Guide to League of Legends Situational Items - Mobalytics
LoLCooldown
League of Legends: A Guide to Understanding Ability Haste
LoLCooldown
TIL you can have up to 89,164% Cooldown Reduction on your ultimate in a Summoner's Rift game. This means that you can use you R almost twice as often as in URF. :
League of Legends Items Guide: Situational Items - Mobalytics