A question about the crit system

Hey, Rioters. I have a question about what system you use for crits in league? I did some research into the system they use for Dota 2; Pseudo-random distribution and true-random distribution, in which pseudo makes the chance of something increase the more it doesn't happen. The true random system is truly random, which means you could crit 4 times in a row with 10% crit chance or not crit at all for 6 shots even with 80% crit (something which has happened to me while playing Dota as PA). I'm interested in knowing which system league uses, so I can time my autos so that I can win trades easily by just walking up and getting off a critical strike with my 10% crit chance then walking away. This'll also allow me to time the enemy crits and back off when I know they are going to crit soon.

Regards

• Hybrid Cub; and main.