Hearthpwn

I did not track the stats, but i climbed pretty easily from rank 500 to rank 18 legend

Mulligan for the early minions except for scarab, you want him in mid/late game to help you with the discover hability.

Cards Choice Explanation:

Tunnel Trogg is a powerful early minion, similiar to a Mana Wyrm, but you can play in curve your minions and buff his attack

2x  Lightning Bolt   its a good removal on early game and buffs Tunnel Trogg

2x Jeweled Scarab because shaman has probably the best 3 drops in the game and you can choose wich card would help you in a better way. At first i was trying 2x Lightning Storm and 2x Hex , but they are situational cards and you can get them from Jeweled Scarab and i liked it.

2x Fireguard Destroyer good sinergy with Trogg

1x Bloodlust i won a lot of games with a 12 or 15 damage bloodlust

UPDATE: My friend Nalguidan picked at rank 4 with the deck

UPDATE 22/11

I tracked some games today and yesterday, 33-15 so far with a few changes i made to the list by reading all your comments.

 -1 Jeweled Scarab  +1 Ironbeak Owl : it was hard to battle the board against deathrattle rogues and the owl its really good in a lot of matches.

-1 Tuskarr Totemic +1 Unbound Elemental: after reading your comments i tried 2 Unbounds but Tuskar is still good for me, so i decided to run 1 of both.

-1 Piloted Shredder+1 Defender of Argus: Argus is always good in shaman, i could not decide if i wanted to remove 1 shredder of 1 destroyer, its a close choice

About Brann Bronzebeard and Neptulon, i tried them and the meta is too fast for them, if you are facing a lot of control decks they are a good option though.

Mulligan Guide

General: Tunnel Trogg, Haunted Creeper and Totem Golem are always a keep, if you have one of those in hand you can keep Flametongue Totem too, and if you have the coin you can keep a 3 drop also.

VS Druid: Lightning Bolt or Crackle (to kill Darnassus Aspirant).

VS Hunter: Lightning Bolt and Earth Shock / Ironbeak Owl to control early board.

VS Mage: Lightning Bolt to kill Mana Wyrm, Earth Shock / Ironbeak Owl to silence Mad Scientist or Doomsayer (dont silence scientist unless you know its tempo mage).

VS Paladin: Earth Shock / Ironbeak Owl to control early minions, Lightning Storm.

VS Priest: Lightning Bolt for Northshire Cleric, Hex  and a 4 drop if you have coin (not Argus).

VS Rogue: Lightning Bolt for their 3 drop, Earth Shock / Ironbeak Owl because it could be deathrattle rogue.

VS Shaman: Lightning Bolt to kill Tunnel Trogg, Lightning Storm.

VS Warlock: Earth Shock / Ironbeak Owl, Hex, Lightning Bolt instead of Hex if you know its zoo.

VS Warrior: Hex and a 4 drop if you have coin (not Argus).