For many years now, Jund and Abzan have defined midrange decks in Modern. The combination of efficient disruption in Thoughtseize and Inquisition of Kozilek, backed by the best removal in Abrupt Decay, Lightning Bolt, and Path to Exile, make these decks the best at interacting with the fast linear decks like Affinity and Infect. You also get to trump early creatures like Wild Nacatl and Goblin Guide with the likes of Tarmogoyf, Tasigur, the Golden Fang, and Siege Rhino. However, these decks now have somewhat of a weakness to the Jeskai Nahiri decks, which can out card advantage Green-based midrange decks with Snapcaster Mage and Cryptic Command while applying real pressure to end the game with Nahiri, the Harbinger. SCGBlue seems to think the answer is to cut the third color and go leaner and meaner:
B/R Midrange — Modern | SCGBlue, 5-0 Modern League
Creatures (18)
2 Grim Lavamancer
4 Dark Confidant
4 Goblin Rabblemaster
4 Pack Rat
4 Simian Spirit Guide
Spells (19)
2 Kolaghan's Command
2 Terminate
4 Lightning Bolt
2 Dreadbore
3 Duress
4 Inquisition of Kozilek
2 Blood Moon
Lands (23)
1 Mountain
5 Swamp
2 Blood Crypt
3 Polluted Delta
4 Blackcleave Cliffs
4 Bloodstained Mire
4 Mutavault
Sideboard (15)
1 Blood Moon
1 Duress
1 Terminate
3 Anger of the Gods
4 Fulminator Mage
3 Relic of Progenitus
2 Vandalblast

Buy This Deck From CoolStuffInc.com
This deck does a couple of very interesting things making it an exciting choice in this metagame. You still have all the efficient removal to deal with the creature decks. You even pick up Dreadbore to deal with Planeswalkers like Nahiri. The difference is really in the threats. We’re not dealing with Tarmogoyf and Siege Rhino anymore. This deck plays threats better against removal spells which can threaten to end the game more quickly. Goblin Rabblemaster and Pack Rat are great at fighting through removal to continue applying pressure to a card like Nahiri or to chip in the last few points of damage so you can Lightning Bolt your opponent to death. On top of that, Dark Confidant is still an absurd card advantage engine if it goes unanswered. So, what’s the biggest advantage of this deck? You’ve got Simian Spirit Guide to turbo out these threats against an opponent who’s unprepared.
The biggest upside of playing this style of deck over something like Jund or Abzan is you get to play main deck Blood Moon. This is a fantastic card in the current format, as it can single-handedly beat other midrange and control decks, while also blanking lands like Inkmoth Nexus and Urza lands. The card only gets more powerful when you can cheat it into play a turn ahead of schedule, or after letting your opponent think you won’t have enough mana to cast it. The combination of efficient interaction, powerful threats, and Simian Spirit Guide to jump a turn ahead of your opponent may make this a great option to trump the midrange mirrors in Modern.