This article explores sideboarding in Flesh and Blood as a core competitive skill rather than a pre-game formality. It frames sideboarding as the deliberate reshaping of a deck’s identity—through philosophy, equipment choices, and card adjustments, to meet the specific demands of each matchup. By examining matchup archetypes, common mistakes, and transformational sideboarding strategies, the article emphasizes preparation, intention, and consistency as the true margins of victory. Ultimately, it argues that mastering sideboarding is one of the most reliable ways for players to gain an edge as the Classic Constructed format continues to evolve.