To begin with, I am not the best english speaker in the world, you probably gonna find a lot of misspelled words, but we have to live with it. ;)

The reason to why I have choosed Olaf is that i like him and I usually plays quite good with him.
I like Olaf becuse he is a bit of a mixture, he has a big damage and also a lot of hp.
In my opinion that make her to a very good champion..
I've done this Olaf to a very offensive hero, just bought offensive things, if you want you can buy 2 Warmogs and remove the Phantom dancer

I am not good att runes and masteries, but I have made a proposal.
I haved choose a lot of Armor Penetration, Attack Speed and Crit.

Like I sad, I am not good att runes and masteries, but it's my proposal, but it can certainly be improved.

I love to play with an offensive Olaf, that is the reason to why I only have choosen offensive items.
If you have a good start and gets feeded, play offense, but if your oppenents have a better start than you, it can be better to buy more hp things..

There, hope you are testing Olaf and think it's as fun to play with him as I think.
two great combinations are Olaf + Ashe, and Olaf + Morgana.
Good luck.

with best regards / Hv ruler