abilities
Why draven top?
It's easy, draven benefits from being solo in lane. You have enough skill potential to 1v2 if you are even 1 kill ahead. About kills, this champ is one of the best for low elo. Why? Just think like that. You have 150 stacks in minute 4 or 5 and then you do a kill which is an first blood. It is a +1000 gold because of your treasure hunter and passive (also first blood +100 gold) and then you can take plates or help on grubs.
Summoners
Draven
Draven has one big weakness also like vayne top. You sacrifice a tank or bruiser for draven. Of course if enemy has like 4 ranged champions then it's better to have a draven but just remember that I have other guides and it's not the best blindpick at all.
Runes
items
Win conditions
You need to teamfight and take kills. You cannot fall behind and also objectives really benefit for draven. Just make sure you apply everything in the guide to win and you should be good to go.
Important
Draven is not an easy champ. He needs practice and if you loose your game, its probably not because of the guide (which isnt the best, it is just for starters and medium advanced draven players, not for the best of the best.) but because of your mechanical skills. You need to play draven a lot on top to master him like any other hard champion.