I'll analyze sideboard card usage in Modern Azorius Belcher decks for you.
Based on tournament data from Modern Belcher decks since early 2024, the most common sideboard cards are Consign to Memory (appearing in 1,275 decks at an average of 3.16 copies), Harbinger of the Seas (1,199 decks, 2.43 average), and Into the Flood Maw (1,001 decks, 1.53 average). Other staples include Mystical Dispute (768 decks), Portable Hole (677 decks), Flusterstorm (675 decks), Unable to Scream (606 decks), and Tormod's Crypt (595 decks). Force of Negation shows up in 542 decks, while niche options like Torpor Orb (113 decks, 1.56 average), Grafdigger's Cage (155 decks), and Spell Snare (350 decks) handle specific matchups.
The sideboard strategy emphasizes interaction and hate pieces. Consign to Memory and Into the Flood Maw provide flexible answers, Harbinger disrupts manabases, and the suite of counterspells (Mystical Dispute, Flusterstorm, Force of Negation) protects the combo while disrupting opponents. Graveyard hate is covered by Tormod's Crypt, Unable to Scream, and Grafdigger's Cage, while Torpor Orb shuts down ETB-based strategies.
Sources: Data aggregated from 55 Modern tournaments between September 16 and October 16, 2025: 78.2% MTGO, 21.8% Melee. Recent examples include:
https://www.mtgo.com/decklist/modern-challenge-32-2025-10-0312819547
https://www.mtgo.com/decklist/modern-challenge-32-2025-10-1212819536
https://www.mtgo.com/decklist/modern-challenge-32-2025-10-1212819532