The most popular and successful lineup at the moment is Evolve Shaman, Tempo Rogue and Combo Priest. There is a very good reason for that: those decks do very powerful things that no other decks currently can match (mostly getting a lot of stats on board extremely quickly and bursting heroes down). Now you might know I am not very fond of aggro decks and the idea of playing mirrors that are mostly determined by starting hands did not appeal to me, so I looked for an edge elsewhere.
The obvious place to start is Warrior, as Rogue and Shaman share a weakness to Control / N'Zoth Warrior variants, so you can swap one of the default decks with Warrior and force a Warrior ban, getting a small edge. After doing extremely poorly with Quest Shaman at first, I got the hang of it and realized that is extremely well rounded and doesn't really have bad matchups out of the common decks, so I locked that deck in as well as since Ienjoy having the opportunity to play Hearthstone every round and not only play matchup roulette. I wanted my third deck to also have favorable matchups against Rogue and Shaman and, well, I couldn't find any obvious one by looking at stats. I talked with Eddie who suggested Resurrect Priest (also known as Big Priest without Barnes). I was a bit skeptical at first but as I practiced I did better and better with it. I started with his Bucharest-winning list then made some small changes for the open cup meta.
One thing I told myself I would do after witnessing Eddie's victory is to stop relying so much on statistics. They are very useful when it comes to quick mulligan advice or to get an idea which decks are the most popular, but the '5 to legend' global winrates will be very different from the winrate a top player can get. The key is to find out which decks have higher ceilings and to navigate towards decks that suit my play style and from which I can extricate the more obscure edges.
So after tuning the lineup for 10 or so open cups this is what I ended up with:
Warrior is very bad against N'Zoth Rogue, Malygos Druid, Highlander Hunter, Highlander Mage, so there will be some trouble or auto-losses against dedicated Warrior target lineups. However, those decks are all lacking in early interaction and can't beat the default lineup so we're just going to have to hope to get through the initial rounds. This is why there is no Hakkar in the Warrior list, as Druid would be the ban and it is not necessary against any other archetype. There is a Zephrys the Great though, which is flexible enough to be useful in any matchup and can break the mirror or other control matchups. I would like to avoid running Brewmaster / Seance but they are a necessary evil to win the Elysiana mirrors. These matchups are pretty fun though as they require a lot of situational awareness to know if it is better to get an extra Elysiana or an extra N'Zoth, for example. Against most lineups you have the luxury of banning Combo Priest, Quest Shaman or even Evolve Shaman, as this lineup farms Tempo Rogue and most Warriors as well. I know the Shaman and Priest matchups against Rogue are not really favored according to statistics but that is not my experience at all over a pretty significant sample size.
I would highly recommend this lineup if the meta does not shift significantly.However, all these decks will require a lot of practice, especially to navigate control mirrors. Just remember that as good as Warrior is against Rogue and Evolve Shaman, it is way way worse against the anti-Warrior decks and requires a lot of mastery to pull off an occasional win. My first round involved a game that took 49 minutes and went to the turn limit double face explosion.... so yeah that can happen. Note that draws count as both a win and a loss on Battlefy and won't be a rematch.
Shout-out to Odemian who inspired my Warrior list and to Eddie for the Resurrect Priest idea! Shaman is super standard but remember to always use the best Shaman, King Rastakhan.
See you in Texas!