Since the release of Modern Horizons, graveyard decks using Hogaak, Arisen Necropolis have had an enormous impact on the Modern metagame. After early signs of the metagame being unable to self-correct, such as players adopting large amounts of main-deck graveyard hate and the Hogaak deck still boasting high win rates, we restricted Bridge from Below to weaken the deck.
Since then, the results of Mythic Championship IV in Barcelona, several Grands Prix, and other tournaments have shown that Hogaak continues to have a high win rate and oppressive effect on the metagame. In looking at the evolution of the archetype over time and the variety of successful ways to build the deck, it's clear that the card Hogaak, Arisen Necropolis is the crux of the problem. Therefore, Hogaak, Arisen Necropolis is banned.
Coming out of this period of an unhealthy Modern metagame, we want to avoid taking a half step that once again leaves the metagame in a place where it can't self-correct. Over the past year, graveyard-based strategies have been occupying a large portion of the Modern metagame, to the point where deck-building diversity is being suppressed. This is reflected in the rise of heavy-handed main deck anti-graveyard cards like Surgical Extraction, Leyline of the Void, and Rest in Peace. We'd like to shift gameplay a little bit away from the graveyard and back toward the hand and battlefield.
The key card enabling the majority of these graveyard-focused decks is Faithless Looting. By our data gathered from Magic Online and tabletop tournament results, over the past year the winningest Modern deck at any given point in time has usually been a Faithless Looting deck. Examples include Hollow One, Izzet Phoenix, and Dredge and Bridgevine variants (both pre- and post-Hogaak's release). As new card designs are released that deal with the graveyard, discarding cards, and casting cheap spells, the power of Faithless Looting's efficient hand and graveyard manipulation continues to scale upward. Regardless of Hogaak's recent impact, Faithless Looting would be a likely eventual addition to the banned list in the near future. In order to ensure the metagame doesn't again revert to a Faithless Looting graveyard deck being dominant, we believe now is the correct time to make this change. For this same reason, we're choosing not to unban Bridge from Below at this time.
Knowing that these changes will already shake up the metagame, we consider this a good time to review cards currently on the banned list. Just as was our philosophy in unbanning Jace, the Mind Sculptor and Bloodbraid Elf last year, we recognize that over time the power level of Modern increases naturally as the card pool grows. Cards that were added to the banned list on pure power level may now be more appropriate in context of a more powerful metagame. We believe the Modern metagame and power level are in a place where Stoneforge Mystic is now an appropriate inclusion in the card pool.
The danger in reintroducing Stoneforge Mystic, and the reason it's remained on the banned list up until this point, is that it's at its strongest against straightforward decks that play to the battlefield. While we think it's unlikely, there is a scenario where Stoneforge Mystic could come to suppress this type of gameplay, in which case we would re-examine its legality (similar to Golgari Grave-Troll's history in Modern). Instead, our hope is that as gameplay becomes less graveyard focused, Stoneforge Mystic serves as an enticing draw for decks to refocus toward the battlefield, creature combat, and card advantage