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
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.
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).