Hearthpwn

This is the deck that I used to reach Rank 1 so far... will be going for legend tonight or this weekend.

This deck is somewhat inconsistent... even though my win rate with it is over 50%, it is sometimes go like this: I lose 6 times in a row and then I win 8 times in a row.
Decent chances against aggro and midrange. Usually loses to Control Paladin. And against priest you need to rush.

Muligan advice:
You want to have a 1 drop and 2 drop and actually not every 3 drop is good in starting hand
For 1 drops prefer Alley Cat, if you have more than one in Mulligan mulligan the other ones.
for 2 drop Dire Wolf or Razormaw are good if you have one drop, if you don't keeping a second 2-drops is a good way to go then. Keep Gollaka Crawler against Warriors, Rogues and Druids (token druids have Patches lately)

Most of the time good starting hand with a coin is 1-drop, Direwolf or Razormaw and a second 2-drop (which can be Direwolf or Razormaw or any other 2 drop) and a Bow (or Animal Companion if there was no bow in Mulligan. if you don't have one drop coin out 2 drop (though try not to play razormaw on empty board, so do some other one)

Without coin it is same idea, but it is Bow or animal companion or a second 2 drop, as you can have both.
I don't recommend keeping 3 drops other than bow and Animal Companion.

As for Houndmaster... if you have 1 drop, 2 drop, 3-drop, Houndmaster in your mulligan, you can try to keep it, but it is risky... as you might not have board on turn 4

Also do not waste time getting murloc crab into this deck... it breaks tempo way too much, if you facing murloc deck then bow is your main murloc killer...