User blog comment:Deshiba/Are you Critting me !?/@comment-8225465-20130518143303/@comment-8225465-20130519095941

Yes, it works both sides. I can still remember me playing Lux, when accidently missing my cage and hitting enemy jungler in the brush. I can remember doing golems with low HP when Karthus ulted to kill his midlane opponent.

You don't know exactly when enemy's ult is ready, you can suppose when it runs out of cooldown. You can see enemy's items and suppose "He has 20% chance for crit, I have 30%, so trading with him can go for my favor". Of course there is a chance that he crits me 5 times in a row and I will not even once, and vice versa. "High risk, high reward situation", isn't it?