4c Spreading Seas - Butter Spread

// Lands
4 Seaside Citadel
2 Jungle Shrine
3 Terramorphic Expanse
4 Arid Mesa
4 Misty Rainforest
1 Scalding Tarn
3 Island
2 Plains
2 Forest
1 Mountain

// Creatures
4 Bloodbraid Elf
3 Acidic Slime
3 Sphinx of Jwar Isle

// Spells
4 Spreading Seas
4 Convincing Mirage
4 Ardent Plea
4 Captured Sunlight
4 Ajani Vengeant
4 Day of Judgment

// Sideboard
SB: 4 Pyroclasm
SB: 4 Rhox War Monk
SB: 4 Baneslayer Angel
SB: 3 Pithing Needle

This is basically Gerry Thompson's Spreading Seas deck, except it has a better anti-Boros sideboard, and it has Acidic Slime over Sphinx of the Lost Truths because getting something on the board now is generally preferred to getting something on the board later -- and it can handle things other than lands, such as Eldrazi Monument.

With 45% of the entire deck (79.4% of the nonlands) being land disruption of some sort, you'll have a solid chance of getting the opponent to a mono-blue deck.

It has essentially auto-win game against every non-U three color deck (Jund and Naya) and every 4+ colour deck. It basically autoloses to Boros game 1, but picks up g2 and g3 fairly easily with the sideboard (but not as easy as it looks). Pyroclasm makes a large difference and is much better than Deft Duelist because it can clear out Geopedes and Step Lynxes, while Duelist just blocks the bad cards like Goblin Guide.

The Pithing Needles are for when you go against UW Fog, which may be this deck's worst matchup. They also work against Eldrazi, a relatively untested matchup.

It's a still relatively unexplored deck and it's pretty much a meta choice. It's great if your field is 33% Jund because you WILL WIN AGAINST JUND, but other than that... who knows?

We'll need more testing.

BUT STILL... AUTOWINS AGAINST JUND!