INTRODUCING: Give Them The D! (not to be confused with "Give them the D" with no exclamation point)
This is a midrange rogue deck. I was annoyed at how tempo was just getting run over by undertakers, pre-nerf, and I decided to make this deck. Give them the D, is short for... give them the defense. This is a board control deck. Rarely will you be able to cheese out a win, but you actually still can. On turn 5, with a weapon out and a minion on board, prep sword oil, sword oil, is like casting 2 fireballs for 5 mana. Think about that for a moment. 2 fireballs for 12 mana. Did I forget to mention that you still have a second swing? Make that 3 fireballs. If you have blade flurry, that third fireball just kills everything including your opponent! Basically it turns the third fireball into apocalypse mode. Seriously, when I get this prep- sword oil combo in my hand. I'm literally like holy crap, what is happening here, is this real?
Mulligan strategy
Most mulligans you go for zombie chows and backstabs. With control you can get a bit more greedy. If you have 1 zombie chow, you can get super greedy and go for shades of naxxramas. Against warrior, I'd keep a zombie chow but I wouldn't mulligan for a zombie chow. Chows keep armor down and when they die the warrior usually isn't even harmed anyway due to armor generation. And if the warrior expends a war axe charge on your chow, big deal.
Against paladin, zombie chows are freaking amazing. Always keep them. Play around truesilver decent enough and you probably win. Tirion is the biggest hurdle so if you can, keep sabotage, but keep in mind whether or not you combo it, you won't destroy ashbringer.
Mech Mage is the hardest match up in my experience. But still very winnable. Van cleef is very good in the match up it turns out. So is blade flurry. But still mulligan for backstabs, zombie chows, and si7 agents. When I have a decent start with in this match up, the main reason I lose is because of crazy goblin blastmage rng.
Against hunter + zoo, same deal. When in doubt, go for zombie chows and backstabs. Keep a shade if you suspect handlock.
I guess the last class I will cover is druid because that class is also pretty difficult lately (although this particular version of the deck is 5-2 vs druid) Mulliganing zombie chow really doesn't do much vs this class. It isn't bad to keep but I generally aim for shades, si7 agents, backstabs, sludge belchers, loatheb, and azure drake. Can't get too greedy though cause some drop their own shades early too.
The deck's worst enemy is Dr. Boom. Heck, any deck that tries to win by establishing board control... should despise that card. It has singlehandedly turned around so many games and made so many games unwinnable, even though I have BGH in the deck. If you want to fit a dr. boom in, by all means go ahead. I don't have it yet. Whatever you do, don't cut gallywix and even ragnaros is pretty important. I wouldn't even cut van cleef but I guess it could work out. Maybe cut a zombie chow if you're feeling daring (zombie chows are good, really good in this deck).
I had a 9 win streak with the deck tonight. Pretty good lately for me in gvg.
I ended the night with a 65% winrate over 45 games (I played a ton tonight).
edit:
Gonna add a short excerpt for warrior. The general consensus seems to be that midrange rogue is very disadvantaged against control warrior. I actually beg to differ. Shade of naxxramas is pretty much the best card you get mulligan for. But zombie chows keep armor down really well. The goal is to shave off armor as much as possible while your shade grows, and then play a sludge belcher or better yet, a loatheb, and start hitting face. Play around brawl and set up for a sword oil blade flurry combo or two, and you'll win. Also, don't bother dropping si7 agents or autobarbers on curve. They just die to weapons. Almost always try to get the extra value from their on play effects. Even taking out the second half a sludge belcher with the autobarber can be a big deal. Generally the goal in this match up is to make it as AWKWARD and EXPENSIVE as possible for the warrior to remove your stuff.
There are 3 legendary cards that will often ruin your day. Sylvanas. Baron Geddon. And Dr. Boom. No surprise here because all three of these legendary cards are designed to fight for board. Shades right before 7 mana is a no no because on turn 7 baron geddon kills it for free. The last tip is for gallywix. Brawl is almost worthless I find. Play around shield slam and shield maiden... executes happen and they suck but at least you can kill something just with hero power execute.