By Tangent444, Gastonagustin, NHoff, and Nesabethan



— Introduction —


With the return of Master League (ML) in GO Battle League (GBL) Season 4, we’re back to highlight some of the top lines and core breakers. Once again, we have a solid picture of how the meta looks thanks to early looks at Season 4 from Ytxpikachu for both Open and Premier and a Season 3 Premier summary from Pokebrains. Master League is a condensed meta with a lower number of viable picks as compared to CP capped leagues, which makes identifying core breakers challenging. For this reason, only three core breakers are shown for each trio core, and you will likely want to place a greater emphasis on Pokémon within the trio core that are “Best vs Trio”. And as if it’s a spoiler for the following article, Best Buddy Dialga remains the center around which the Open ML meta revolves. So let’s get to it!


What is a Core?


A core is a pair of Pokémon that synergize well together by covering each other’s weaknesses, and trio cores are composed of multiple powerful duos. Therefore, any single Pokémon in the trio core can often be substituted for another partially complementary Pokémon to create a solid line that’s less predictable. Core breakers are Pokémon that generally perform well, even in a loss, against all members of a duo or trio core. You might only face two of the three shown in any given battle, but bringing one of these core breakers means you’ll be well positioned no matter which of those duos you see.


How does the Graphic work?


Each GBL meta-defining trio core is surrounded by three core breakers. Each segment of the encircling ring reflects its matchup with the respective trio core Pokémon. A Win (dark teal) or Loss (dark gold) generally indicates the outcome in even-shield scenarios, and these matchups are less likely to flip due to slight energy differentials. Even (grey), Narrow Win (light teal) and Narrow Loss (light gold) reflect which way the matchup generally trends and implies that IVs and slight energy differentials might play a larger role in the outcome. Importantly, Pokémon walled by one of the three were often not considered despite having solid matchups against two of the three. As these trios are composed of multiple strong duos, sometimes one of three Pokémon are replaced with another pick to reduce predictability or better counter the current meta. Try integrating these core breakers into your lineup to counter some of the top teams in GBL.


— Terms —


Note that 0/1/2S refers to the even-shield scenarios in simulations from PvPoke. All wins or losses mentioned are even-shield scenarios with zero starting energy unless otherwise stated. Stat Product (SP) and IVs are occasionally referenced. Exclusive moves (*) cannot be acquired by regular TMs and are either legacy or obtained through previous events, purification or use of an Elite TM.


— Giratina Origin + Dialga + Melmetal —

  • Giratina Origin Shadow Claw + Shadow Ball + Ominous Wind

  • Dialga Dragon Breath + Iron Head + Draco Meteor or Thunder

  • Melmetal Thunder Shock + Superpower + Rock Slide

This trio was the face of Master League on its introduction in GBL Season 1, and continues to be a force. This core doubles up on the dominant Steel types of the Meta, and protects them with Giratina Origin’s resistance to Fighting and Fire type damage.




Groudon Mud Shot + Fire Punch* + Earthquake


The arrival of Fire Punch for Groudon in Season 2 put a significant dent in the viability of this core. It has a narrow loss to Giratina Origin, losing 0S and 2S but having a chance at a close 1S matchup with a shield bait, but has strong matchups with the Steel types. Groudon wins all even shield scenarios with Dialga, but note that it could come at a shield disadvantage. Groudon wins 0S with Earthquake, but not with Fire Punch. However, it loses 2S if it has an Earthquake shielded.


Rhyperior Mud-Slap + Rock Wrecker* + Surf or Superpower


Before Groudon received Fire Punch, Rhyperior was the specialist in Master League for handling the Steel types and continues to provide value in this role. It requires one shield investment to take down Dialga with just the fast move, which means you need to be careful not to get caught shieldless as Dialga wins 0S by landing an Iron Head. Rhyperior loses 0S and 2S matchups to Giratina Origin, but wins the 1S matchup without needing a shield bait.


Snorlax Lick + Body Slam + Superpower or Earthquake


While Groudon and Rhyperior are targeting the Steel types of the Core, Snorlax is on a mission to seek and destroy Giratina Origin. As a Normal type, Snorlax double resists Giratina’s common all Ghost moveset. And even if Giratina is carrying Dragon Pulse, which it rarely does, Snorlax still wins the 1S and 2S matchups and only drops the 0S matchup in a close loss if it is not running Earthquake. Speaking of the second move, Snorlax carries one of Superpower or Earthquake in order to threaten the Steel types. This makes its matchup with them fairly even and it will come down to whether it can land these moves or successfully bait shields with Body Slam.


— Kyogre + Dialga + Togekiss —

  • Kyogre Waterfall + Surf + Thunder or Blizzard

  • Dialga Dragon Breath + Iron Head + Draco Meteor or Thunder

  • Togekiss Charm + Flamethrower + Ancient Power or Aerial Ace

This trio became increasingly popular with the rise of Fire Punch Groudon. The core is very tight, having coverage for just about everything and limiting core breakers. However, its reliance on fast move damage can make it more challenging if your Pokemon are not aligned correctly against their appropriate Meta target. It could take some clever strategy to pull it out of a tough spot. For example, using Dialga as a switch in order to draw out an opposing Melmetal, which Kyogre can take down and later leaves Togekiss with two shields to try and take out the remaining two Pokemon.




Melmetal Thunder Shock + Superpower + Rock Slide


Melmetal has strong matchups with Togekiss and Dialga, only needing to fear Dialga in the 2S scenario if it debuffs itself too many times with Superpowers that get shielded and only worrying about getting hit unshielded by a Flamethrower from a Togekiss with energy. Kyogre is the core’s strongest answer to Melmetal, however it loses the 2S scenario and also drops the 0S scenario if Melmetal has just one Thunder Shock of energy advantage.


Mewtwo Psycho Cut + Psystrike + Focus Blast


Mewtwo can go toe-to-toe with all three members of the core. Mewtwo’s second move choice has a number of options, but for this core you would want to have Focus Blast as an option as it picks up more scenarios against Dialga and Kyogre than the other moves would. Against Kyogre, Mewtwo wins the 0S matchup with straight Psystrike, but loses 1S and 2S. However, it can land a Focus Blast to win the 1S matchup with shield bait. Against Dialga, Mewtwo has win conditions in 0S and 1S by landing a Focus Blast, can potentially win 1S with straight Psystrike, but loses 2S. Against Togekiss, Mewtwo wins 0S and 1S with straight Psystrike but loses 2S.


Mew Shadow Claw + Dragon Claw, Psyshock, Wild Charge, Focus Blast, or many more!



This core is very tough to crack, which meant we resorted to a Pokemon like Mew to fill out the core breakers. Seldom seen in the Master League Meta, it could be wielding Wild Charge to threaten Kyogre and Togekiss, or Focus Blast to threaten Dialga. Question is: What movies is Mew carrying and does that fear cause you to shield a Dragon Claw with Togekiss, only to later get hit by a Wild Charge?


— Groudon + Dialga + Mewtwo —

  • Groudon Mud Shot + Fire Punch* + Earthquake

  • Dialga Dragon Breath + Iron Head + Draco Meteor or Thunder

  • Mewtwo Psycho Cut + Psystrike + Focus Blast/Shadow Ball/Flamethrower/Ice Beam

What’s this, our third core with Dialga at the center? If that doesn’t describe Master League in a nutshell, I don’t know what else would. This core trio has gained popularity due to the massive power of its charge moves, while covering a wide variety of the Meta with few glaring weaknesses.




Togekiss Charm + Flamethrower + Ancient Power or Aerial Ace


Togekiss is very tough for this core, if Togekiss has shields in play. Togekiss defeats Groudon in 0S using Flamethrower or Aerial Ace (don’t get cute with Ancient Power, which makes the matchup close enough for small lag to impact it), narrowly loses 1S (which can easily be a win depending on extra fast moves or lag), and wins 2S. Togekiss also wins 2S against Mewtwo and Dialga. In particular, it escapes from the Dialga matchup with most of its HP intact after investing both shields, and forces a shield from Dialga.


Garchomp Mud Shot + Outrage + Sand Tomb or Earthquake


Garchomp has winning scenarios against each of the core members. Against Groudon, Garchomp can win with Sand Tomb shield baits, or if it correctly calls a Fire Punch shield bait and takes it unshielded. Against Dialga, Garchomp can win with Sand Tomb shield baits, or by landing an Earthquake unshielded. Against Mewtwo, Garchomp can win 1S with straight Outrage, can win 2S with a Sand Tomb shield bait, but loses 0S. In this sense, Garchomp has winning scenarios against all three core members, and will keep each one guessing as to whether it is throwing a Sand Tomb or throwing a hard hitting charge move.


Gyarados Dragon Breath + Aqua Tail + Crunch OR Outrage


Seldom seen in Open Master League, Gyarados is a specialist that handles Groudon with ease, and has winning scenarios with Dialga and Mewtwo. It can win 1S Dialga with shield bait if running Aqua Tail and Outrage, and can win 1S Mewtwo with shield bait if running Aqua Tail and Crunch. Dragonite is more commonly used in the Anti-Groudon role, but Gyarados would be the better choice for cracking this specific core.


Hope you found the graphic and article helpful, and thank you for taking the time to read the full write-up. Please share the post if you found it useful and good luck battling out there!