So im a jungle main and i have been trying olaf 
recently. he's pretty fun except for the fact that i go against a full crit strike champion every game. i tried countering with armor(which i now know counter damage) but it didn't work. how does one counter a crit strike champion?
Either
A) Kill it
B)
for an additional 20% reduction to crit and 
for 10% reuction to AA
Trick with Olaf is you NEED to be ahead. Without a lead you won't be super OP and will just be beat into the ground. Poke champs down with a maxed Q before ulting and all inning. To get ahead target mages, olafs ult allows you to just desroy them even under tower since they rely on cc to live.
To win get wing boots, deadmans, and spirit visage(olaf is about lifesteal and spped). Randuins is ok but really if you are behind enough that a squshy is overtaking you, you have bigger more basic problems.
Last edit, go volley bear if you are looking for a tank jg instead. Volley is just a beast this season.
Randuins + tabis, no "crit strike assassins" will kill you. ADCs are a different matter because most can kite Olaf.
