Announcement Date: July 21, 2021

Historic:

Brainstorm is suspended.

MTG Arena effective date: July 22, 2021

In the banned and restricted announcement for Historic in June, we mentioned that we were keeping an eye on the high play rate and perceived dominance of blue-red decks in general and Brainstorm in particular.

As we watched, we saw an interesting pattern emerge. Though decks like Izzet Phoenix and Jeskai Control represented a metagame share that usually indicates a dominantly powerful deck, their win rates have generally been fair and healthy. For example, Izzet Phoenix was approximately 30% of the metagame in the July Strixhaven League Weekend, which is a very high percentage for one deck to claim. But its win rate there was only 51.5%, far from dominating or threatening. This matches our internal data, which consistently showed Izzet Phoenix with a win rate a bit above 52% and Jeskai Control a bit above 51% in high-level Best-of-Three play.

Given these lower win rates for Izzet Phoenix and Jeskai Control and the presence of multiple other archetypes with strong records against both decks and the rest of the field, we expected to see the metagame share of these decks decline over time. Though we saw some reduction—the combined metagame share among high-level players in Best-of-Three ladder play declined steadily from 17% in mid-June to 14% more recently—these two decks have remained the most played there, usually by a good margin.

When evaluating a format, our goals are generally to create a balanced, fun, and diverse metagame. While decks like Izzet Phoenix and Jeskai Control are not showing win rates that threaten balance, their steadily high metagame share is certainly harming deck diversity, which in turn reduces the fun of the format. While we are seeing some motion to correct this, the rate of change is too gradual to quickly address the format imbalance. To improve format diversity, Brainstorm is suspended in Historic.

While our most recent actions in Historic have been bans—such as those for Time Warp and Thassa's Oracle—those were cases where we had clear and convincing data showing the cards were problematic. In this case, the data is less clear, and that is exactly where we prefer to utilize suspension. We will continue to monitor the Historic meta closely to see if it reaches a point where reintroducing Brainstorm seems safe or if we should move to fully ban Brainstorm.