White-blue decks are all the rage right now in Standard. The control versions are more popular than the midrange ones, but I believe the midrange versions like the one I am playing here are well-situated against the control decks. Similar to the way Blue-Black Midrange has been favored against Blue-Black Control, there is the same sort of correlation with these. The list that Brennan DeCandio did well at the last Open with is what I played in the videos, though I recommend a couple changes to it.
The best part about the deck is how threat-dense it is – there are so many cards that the opponent needs to deal with. The planeswalkers provide enough card advantage that it isn't really necessary to have additional card draw in the decks. If you can keep a Karn, Scion of Urza or Teferi, Hero of Dominaria in play for a few turns that should be enough card advantage to do the trick. Heart of Kiran goes well in these types of decks that can crew it with planeswalkers.
The cards I would take out of the sideboard are Fall of the Thran and Raff Capashen, Ship's Mage. These are two really sweet cards, but it is also hard to figure out exactly where you want them. I would have a card like Baffling End as additional removal to fight the creature decks, and possibly a couple Torrential Gearhulk as a more impactful flash threat in the sideboard. That said, I'm sure Brennan had a good reason for playing them.
The matches went fairly smoothly and according to plan. Luckily, we got to play against multiple control decks to help illustrate how strong the deck is versus those strategies. The gameplan is to eventually run them out of countermagic and resolve a key threat. The sweetest deck we played against has to be the Red-Green Aggro Legendary build, though it's hard to say how competitive that deck is. In the first game we got smashed, but it looked less impressive after that.
White-Blue Midrange allows you to have multiple different gameplans based on the matchup. Being able to not just be a countermagic-heavy control deck is really nice. The deck has plenty of play starting on turn two and can use threats like Walking Ballista as removal. The most difficult aspect of playing this deck is the sequencing and deciding when exactly it is best to deploy planeswalkers. Normally the opponent tries to answer the planeswalkers as quickly as possible, so try to get as much immediate value from them as possible.
White-blue decks have gone from being pretty much only Approach of the Second Sun to one of the most popular color pairs in the format. I know these sorts of decks will be major players at the upcoming Pro Tour, and to be honest they aren't easy to beat.
Thanks for reading,