The ranking system is the most demoralizing, inaccurate, and rigged process in all of EM. Always has been. I've participated in countless ranking sessions, and they are truly sickening. It's all about who knows who, who likes who, who can best fill quotas, etc. There is often not a dimes difference in employees ranked at 85 versus those at 55. It is always about which bosses pound the table for their folks, and there are lots of side deals/agreements between managers (you support mine, and I'll support yours). You can (and many will) fall from top quartile to bottom quartile for no reason, maybe your new boss doesn't like you, or maybe you are just approaching age 50+. Until the culture (dog eat dog) changes, and as long as ranking is directly linked to compensation, no system will work at EM.
Perfectly stated, @zlb+17c2ksEd.