I have just picked up Eldrazi online and have been loving it. I am currently 40-11 with Noloam's 75. That puts me at 78% win loss ratio which is ridiculous. I had trouble the first few times I played the deck earlier this year primarily due to side boarding decisions. The list is similar to a combo deck where it is trying to be very consistent every game and side boarding out the wrong cards can break that consistency and will dilute the power of the deck. Understanding what cards are important in which match ups are critical since we do not have general counter spells or discard which can hit all different types of relevant cards per match up, instants, sorcery, artifacts, creatures esc. Here is the side boarding guide for Noloam's 75 that he and I have been working on for about a week, it covers the most common decks in legacy, there are a few rare ones missing but you should be able to decipher what cards are good and why they are good for other match ups based on this guide.
Eldrazi Stompy
Sideboarding Guide
List
Creatures (25)
4 - Endless One
4 - Eldrazi Mimic
4 - Matter Reshaper
4 - Thought-Knot Seer
4 - Reality Smasher
3 - Simian Spirit Guide
2 - Oblivion Sower
Artifacts (6)
4 - Chalice of the Void
2 - Umezawa’s Jitte
Instants (4)
2 - Warping Wail
2 - Dismember
Lands (25)
4 - Ancient Tomb
4 - Cavern of Souls
4 - Eldrazi Temple
4 - Eye of Ugin
3 - Mishra’s Factory
3 - Wasteland
2 - City of Traitors
1 - Urborg, Tomb of Yawgmoth
Sideboard (15)
4 - Thorn of Amethyst
4 - Leyline of the Void
2 - All is Dust
2 - Ratchet Bomb
1 - Endbringer
1 - Pithing Needle
1 - Karakas
Match Ups
Miracles
-3 Matter Reshaper (No value vs. Swords to Plowshares and Terminus)
-3 Simian Spirit Guide (This is an early game card and the games will go long. Blow outs into over exposure into Terminus cause losses)
-2 City of Traitors (This is an early game card games will go late)
-2 Umezawa’s Jitte (You don’t want to draw both in the late game, it is still fine vs Monastery Mentor, Vendilion Clique and Snapcaster Mage)
+ 2 Ratchet Bomb (Catch all vs Counterbalance, Back to Basics, Angel and Mentor tokens, Blood Moon and Moat)
+ 1 Pithing Needle (Good vs. Sensei’s Divining Top and Jace)
+ 4 Thorn of Amethyst (Slows them down, makes their cantrips less effective)
+ 1 All is Dust (Against a overloaded board of Mentor or Angel tokens, Jace, Blood Moon, Back to Basics and Moat)
+ 1 Karakas (Better lategame than city and it bounces Vendilion Clique/Venser)
+ 1 Endbringer (Good threat and is a great source of card advantage)
Grixis/BUG/RUG Delver
No Boarding (Your matchup is good from the start do not dilute they deck from what it is already doing)
Shardless BUG
-3 Simian Spirit Guide (This is an early game card and the games will go long)
+2 All is Dust (Cleans the board after a stalemate)
+1 Endbringer (Good threat and is a great source of card advantage)
Jund
-3 Simian Spirit Guide (This is an early game card and the games will go long)
+2 All is Dust (Cleans the board after a stalemate)
+1 Endbringer (Good threat and is a great source of card advantage)
Death & Taxes
-4 Chalice of the Void (It gets bounced by Flickerwisp and only catches Swords to Plowshares and Aether Vial. They board out the moms after boarding of course)
+1 Pithing Needle (Good against Wasteland, Aether Vial, Mangara, Stoneforge Mystic)
+2 All is Dust (It is not the best strategy as their game plan is to deny you access to your mana. However, if the games go late and you have your mana it helps clean up the board.)
+1 Karakas (Helps to escape the mana denial plan and bounces Thalia)
Eldrazi
-4 Chalice of the Void (no targets)
+1 Endbringer (Good threat and is a great source of card advantage)
+2 Ratchet Bomb (Shuts down big Endless Ones)
+1 Karakas (Extra land vs Wasteland)
Storm
-4 Matter Reshaper (The card is too slow and has no disruption to their combo)
-2 Oblivion Sower (The card is too slow and has no disruption to their combo)
-2 Dismember (No valid targets)
-2 Umezawa’s Jitte (This card is too slow and has no disruption to their combo)
+4 Thorn of Amethyst (Slows them down, makes their cantrips less effective)
+4 Leyline of the Void (Gets Past in Flames, Cabal Therapy, if they try to flash back with Goblin tokens and Cabal Ritual)
+2 Ratchet Bomb (Gets Empty the Warrens mainly, but can clean up their Lion’s Eye Diamonds and Lotus Petals if they are scared for a Chalice of the Void on zero. Play them before your Chalice hits the board)
Elves
-2 Oblivion Sower (The card is too slow and has no disruption to their combo)
-2 Matter Reshaper (Mediocre, doesn’t disrupt what they are trying to do)
-1 Dismember (You take too much damage, you can get raced afterwards if you have an Ancient Tomb in play since they can swarm you)
+2 All is Dust (If you Though-Knot Seer their Glimpse of Nature or Natural Order, you slow them down and can flush their board afterwards)
+2 Ratchet Bomb (Catch all against since most of their deck consists of one drops)
+1 Pithing Needle (Good vs Deathrite Shaman, Wirewood Symbiotic and Quiron Ranger)
Omni-Tell
-2 Umezawa’s Jitte (This card is too slow and has no disruption to their combo)
-2 Dismember (No valid targets)
-2 Matter Reshaper (The card is too slow and has no disruption to their combo)
+4 Thorn of Amethyst (Slows them down, makes their cantrips less effective)
+1 Endbringer (Stops Emrakul from attacking)
+1 Karakas (Can bounce Show and Tell Emrakul)
Sneak Attack
-2 Umezawa’s Jitte (This card is too slow and has no disruption to their combo)
-2 Dismember (No valid targets)
-3 Matter Reshaper (The card is too slow and has no disruption to their combo)
+4 Thorn of Amethyst (Makes cantrips less effective, slows them down)
+1 Pithing Needle (Stops Sneak Attack)
+1 Endbringer (Stops Emrakul and Griselbrand from attacking)
+1 Karakas (Can bounce Show and Tell Emrakul and Griselbrand)
Lands
-2 Umezawa’s Jitte (This card is too slow and has no disruption to their combo)
-2 Dismember (No valid targets)
-1 Warping Wail (Mediocre too few targets, Gamble and Life from the Loam)
+4 Leyline of the Void (Locks out their Life from the Loam and their Punishing Fire)
+1 Karakas (Bounces Marit Lage and good versus Wasteland)
Infect
-1 Oblivion Sower (The card is too slow and has no disruption to their combo)
+1 Pithing Needle (Shuts down Inkmoth Nexus)
Stoneblade Variants
-3 Simian Spirit Guide (This is an early game card and the games will go long)
+2 All is Dust (Catches all (True-Name Nemsis, Batterskull Germ, Jace, Stoneforge Mystics, Snapcaster Mage, Lingering Soul Tokens, Hierarchs, Sylvan Libraries)
+1 Endbringer (games always go to the late game, so it’s great vs Batterskull and it shoots down Baleful Strix)
Burn
-1 Ancient Tomb (You don’t want to help the burn deck)
-2 Dismember (You don’t want to help the burn deck)
-2 Oblivion Sower (Card is too slow)
+1 Karakas (Better than Ancient tomb)
+4 Thorn of Amethyst (Helps to slow them down and to prevent the Ensnaring Bridge from hitting the board)
Reanimator
-2 Oblivion Sower (This card is too slow and has no disruption to their combo)
-2 Umezawa’s Jitte (This card is too slow and has no disruption to their combo)
-2 Dismember (No valid targets)
-3 Matter Reshaper (The card is too slow and has no disruption to their combo)
+1 Karakas (Bounces the Griselbrand, Elesh Norn and Jin-Gitaxias when they hit play)
+4 Leyline of the Void (Locks out the graveyard package)
+4 Thorn of Amethyst (Makes cantrips less effective and slows them down)
Mavericks
-4 Chalice of the Void (Not enough targets and can they play Cavern of Souls)
+1 Endbringer (Taps Knight of the Reliquary and helps break Standstills)
+2 All is Dust (Helps to clear the board in a standstill)
+1 Karakas (Helps vs Wasteland and Thalia and to make it easier to All is Dust)
Oops All Spells
-2 Oblivion Sower (This card is too slow and has no disruption to their combo)
-2 Umezawa’s Jitte (This card is too slow and has no disruption to their combo)
-1 Dismember (Targets only the Undercity Informer, when they do not have mana up to use it)
-3 Matter Reshaper (The card is too slow and has no disruption to their combo)
+4 Leyline of the Void (Locks out the graveyard package)
+4 Thorn of Amethyst (Makes fast mana less effective, slows them down)
Dredge
-2 Oblivion Sower (Comes out to slowly doesn’t help breaks standstills)
-2 Dismember (Doesn’t help when you are being swarmed)
-2 Umezawa's Jitte (Doesn't help when being swarmed, costs a lot of mana to get live, you'll spend early turns doing other things more effective.
+4 Leyline of the Void (Nullifies their graveyard strategy completely)
+2 Ratchet Bomb (Clears all Zombie tokens made by Bridge from Below)
Manaless Dredge
-2 Oblivion Sower (Comes out to slowly doesn’t help breaks standstills)
-2 Dismember (Doesn’t help when you are being swarmed)
-2 Warping Wail (Though it can counter the first of Cabal Therapy and Dread return, it doesn’t stop the sac flashback for each, which is what enables their Bridge from Below engine)
-2 Umezawa’s Jitte (Comes down to slowly doesn’t clean up standstills fast enough)
+4 Leyline of the Void (Hit their graveyard to lock them out of the game)
+4 Thorn of Amethyst (They have no mana so it will permanently lock the from casting Cabal Therapy or Dread Return)
Grixis Tezzerator
-4 Chalice of the Void (No targets as they run it)
-2 Dismember (No valid targets)
-2 Warping Wails (Not enough targets to keep in post board)
-1 Umezawa’s Jitte (Comes down to slowly doesn’t disrupt what they are doing)
+4 Leyline of the Void (Stops their Thopter Foundry Combo)
+2 Ratchet Bombs (Destroys Thopter Tokens, Thopter Foundry, Ensnaring Bridge and Blood
Moon)
+2 All is Dust (Kills All Planeswalkers, Blood Moon, The Abyss, Nether Void, Thopter Foundry and Thopter tokens)
+1 Pithing Needle (Stops Tezzeret, Jace, Dack Fayden and Thoper Foundry, lots of application)
4c Loam
-4 Chalice of the Void (No targets as they run it)
-2 Warping Wail (Doesn’t hit enough targets to be valued in matchup)
+4 Leyline of the Void (Stops their Life from the Loam lock, Knight of the Reliquary growing and Punishing Fire lock)
+2 All is Dust (Cleans up Board from all their permanents late game)
UR Delver
-1 Ancient Tomb (You don’t want to help the burn deck)
-2 Dismember (You don’t want to help the burn deck)
-2 Oblivion Sower (Comes down too late and makes price of progress even more awkward)
+1 Karakas (Better than Ancient Tomb damage)
+4 Thorn of Amethyst (Makes cantrips less effective, slows down their burn package)
G/B Turbo Depths
-2 Umezawa’s Jitte (This card is too slow and has no disruption to their combo)
-2 Dismember (Too few Targets)
-1 Oblivion Sower(Too slow and doesn't disrupt what they are doing)
+1 Karakas (Bounces Maret Lage)
+1 Pithing Needle (Stops Wasteland lock, Vampire Hexman, Thespian Stage, Knight of the Reliquary, Deathrite Shaman, Sensei’s Divining Top and Expedition Map)
+1 Endbringer (Great Threat and Taps Marit Lage token and Knight of the Reliquary)
+2 Ratchet Bomb (Hits Deathrite Shaman, Dark Confidant, Sylvan Library and Knight of the Reliquary)
12 Post
-2 Umezawa’s Jitte (This card is too slow and has no disruption to their combo)
+1 Pithing Needle (Helps against Expedition Map, Sensei’s Divining Top, Candelabra, Ugin the Spirit Dragon and Eye of Ugin)
+1 Endbringer (Good end game Threat and taps their Primeval Titan, Emrakuls, or Ulamog.)
Aluren
-2 Oblivion Sower (Comes down too slowly and doesn’t disrupt their combo)
+2 All is Dust (Catch all for if the game goes late)
Merfolk
-4 Chalice of the Void (They also run Chalice of the Void and have Cavern of Souls)
-2 Warping Wail (It only hits Silvergail Adept and Curse Catcher but not if they have a lord effect)
+2 Ratchet Bomb (Their Lords are all two drops and helps sweep their board)
+2 All is Dust (Helps to clear the board in a standstill)
+1 Pithing Needle (Hits Aether Vial, Wasteland and Mutavault)
+1 Endbringer (Can target Phantasmal Image and is just better then Warping Wail)
MUD
-4 Chalice of the Void (They also run Chalice of the Void and have Cavern of Souls)
-1 Warping Wail (Not enough targets to use post board)
+1 Pithing Needle (Hits Mishra’s Factory, Karn Liberated, Wasteland, Umezawa’s Jitte and Kuldotha Forgemaster)
+1 Karakas (Helps to avoid Wasteland disruption)
+1 Endbringer (Helps to match their bigger creatures)
+2 Ratchet Bomb (A bad card due to their big mana costs, but better than Chalice of the Void or Warping Wail)
Pox
-2 Oblivion Sower (To expensive to effectively cast vs their land hate)
-2 Dismember (To few targets apart from Mishra’s Factory)
+1 Pithing Needle (Good vs their Lilianas, Wasteland and Mishra’s Factory)
+2 Ratchet Bomb (Good vs Ensnaring Bridge)
+1 Karakas (Helps to avoid Wasteland disruption)
Nic Fit
-3 Simian Spirit Guide (You will go into late game explosiveness is not as relevant)
-2 Umezawa’s Jitte (Not very impressive, only if the run Baleful Strix)
-1 Matter Reshaper (Not very impressive doesn’t pair well vs their fatties)
+4 Leyline of the Void (vs Veteran Explorer, Recurring Nightmare, Cabal Therapy and Eternal Witness)
+2 All is Dust (The primary purpose is to rid the board of Planeswalkers and break late game standstills)
Goblins
-4 Chalice of the Void (They also run Chalice of the Void and have Cavern of Souls)
+2 All is Dust (Helps to clear the board in a standstill)
+1 Pithing Needle (Hits Aether Vial, Rishadan Port and Wasteland)
+1 Karakas (Helps prevent land Disruption, also bounces Thalia if they are running it pasteboard which can assist casting a crucial All is Dust)
Tin Fins
-2 Oblivion Sower (This card is too slow and has no disruption to their combo)
-2 Umezawa’s Jitte (This card is too slow and has no disruption to their combo)
-2 Dismember (No valid targets)
-2 Matter Reshaper (The card is too slow and has no disruption to their combo)
-2 Warping Wail (Too slow and they play more instant speed reanimates compared to traditional Reanimator)
+1 Karakas (Bounces the Griselbrand or Emrakul when they hit play)
+4 Leyline of the Void (Locks out their graveyard package completely)
+4 Thorn of Amethyst (Slows them down, makes their cantrips less effective)
+1 Pithing Needle (Hits Griselbrand or Children of Korlis)
Painter’s Servant
-2 Oblivion Sower (Comes down too slowly and doesn’t disrupt their combo)
-1 Matter Reshaper (Does not interact with their combo enough)
+2 Ratchet Bomb (Helps disrupt the Painter’s Servant Grindstone interaction and can take out pesky permanents like Blood Moon, Magus of the moon and Ensnaring Bridge)
+1 Pithing Needle (Hits Sensei’s Divining Top, Goblin Welder, Grindstone and Jaya Ballard)