[2020] Critical Strike Chance, important laning mechanic

"The critical strike chance changes dynamically depending on the number of basic attack that didn't critically strike. For example, if you have a 30% critical strike chance you guaranteed to have 30 or more attacks that critically strike per 100 attacks. If you don't critically strike for a long time your next attacks have a higher chance of critically strkining."

Direct Quote Credit leagueoflegends.fandom

The reason this is important, with crit based champions, is the more minions in a row that you go without a critical hit. The higher the theoretical chance, that if you choose to risk engaging in a trade with your lane opponent(s), you will crit and easily win the trade or even get a kill. This works even with a small amount of crit chance.

Edit: Further evidence by a study posted on doranslab.gg

The Critical Strike Algorithm

By Justin D. - September 20, 2020