How does "% chance of % cooldown reduction" work?

[kalirion]

I have a ring which gives "4% Chance of 72% Cooldown Reduction". The 75% is clear enough, but what is the 4% Chance related to? Every time I use a skill, there's a 4% chance that the cooldown will be reduced by 72%? Or every time I attack there's a 4% chance that all current cooldown timers will be reduced? Or something else?

[powbam]

Anytime you use a skill with a cool down there will be a 4% chance the cd gets reduced.

[kalirion]

Got it, thanks!

[AH-1 Cobra]

Yeah those 5%-10% chance for reduced C/D procs aren't all that great. They don't happen frequently enough to really plan around, and when they do proc, it happens infrequently enough where I usually ignore it banking on the skill not ever having a CD reduction.

[kalirion]

I guess it could only be a "nice to have" for passive activations that trigger by themselves (%health triggers, etc) and then have longish cooldowns.

[AH-1 Cobra]

I'm not sure the CD reduction procs effect "circut breakers" or not. If they do then they're slightly more useful.

[munchman347]

Those small %'s are only useful if you can stack them up to 20% or more.