Let’s jump straight into the sideboard plans—I’ll show you each of our plans against the major decks:

Affinity

On the Play

Out

In

On the Draw

Out

In

You could argue against Warping Wail because it’s too expensive, but overall you need as many ways as possible to kill Steel Overseer. Pithing Needle can name Cranial Planting, Arcbound Ravager, and Steel Overseer, so waiting for them is sometimes better.

Chalice of the Void for 0 is great when you are on the play, but not so great when you are on the draw since your opponent has already gotten a chance to play them. If you draw Chalice during the middle of the game, I recommend that you set it on 0 like Ivan Floch did against Patrick Dickmann in the semifinals—even if their 0-drops are irrelevant at that point, you have plenty of 1- and 2-drops that you want to be able to cast.

Simian Spirit Guide doesn’t shine on the play since you like everything else—you want the creatures to race—and since you are on the play, you can give up some speed.

Overall this is a fairly even matchup. It’s very important to win the die roll. Know that they play Affinity so that you play Chalice for 0, which isn’t an easy thing to do at a GP.

I managed to win 2 matches and lost 1 against Affinity. Overall, our team defeated it multiple times.

Colorless Eldrazi

Out

In

This is how I sideboarded against Mike Sigrist, but I heard a lot of discussion over this by the rest of the team. Hayne likes Spellskite since it can block Reshaper and redirect a Dismember, someone else liked Ratchet Bomb since it can kill Endless One (which is usually the biggest thing on the board), someone else didn’t like Gut Shot—even if it’s a nice tempo swing, it has very few targets.

Everyone agreed to board out Chalice, though.

UR Eldrazi

Out

In

For this matchup, Gut Shot is a must since they have Eldrazi Skyspawner along with Eldrazi Mimic. Spellskite is worse here since they don’t play Matter Reshaper and play fewer copies of Dismember.

Ratchet Bomb is slightly better since they have multiple 3-drops, but it’s still too slow. Relic of Progenitus exiles lands that got hit by your Ghost Quarters so that you can put those into play with Oblivion Sower.

This is a very tough matchup—the only way to win is to be very fast, so I recommend you mulligan aggressively.

Burn

Out

In

This matchup is incredibly favorable. Sometimes you finish the match without taking damage at all. Chalice for 1 is a powerhouse and Thought-Knot Seer is the best card. It’s very hard to lose.

Infect

Out

In

This is another super easy matchup. It’s the only matchup where you want to cast Chalice for 1 and have some spell with the same casting cost, so don’t be like me and forget that Chalice of the Void counters your spells as well!

BGx

Jund

Out

In

Abzan

Out

In

This is an even matchup. Game 1 you are the aggressor, but game 2 you switch into the control role with Relic and Sower, and your plan is to activate Eye of Ugin with the lands you stole from your opponent.

Ratchet Bomb is the only answer to a 5/6 Tarmogoyf and also kills Spirit tokens when they aren’t held at bay by a Blinkmoth Nexus.

Tron

Out

In

Another great matchup for you as you are very fast and have some disruption like Thought-Knot Seer and Ghost Quarter. Mutavault is very important since it lets you keep the pressure up without overextending into an Oblivion Stone.

Wurmcoil Engine is nearly impossible to beat if they manage to resolve it. The only way is to attack with your team and to Dismember your creature that was blocked by Wurmcoil Engine to avoid your opponent gaining 6 life. Another way to deal with it is with Act of Aggression. We considered playing it in the sideboard just for Wurmcoil Engine. In the end I decided not to, since it is only useful in this matchup and Modern is such a large format that you can’t have a sideboard card only for one deck.

I pretty much covered every important matchup—if you want more information, ask in the comments and I’ll be glad to answer you!