Golgari is a grindy removal/discard deck with Sheoldred, the Apocalypse and Graveyard Trespasser as its best threats, so Scorching Shot answers both: its 5 damage kills Sheoldred (a 4/5) as well as Trespasser and Sentinel of the Nameless City. Redcap Melee stays on the bench. It deals only 4 damage, which doesn't kill Sheoldred, and every Golgari permanent is nonred, so it would make you sacrifice a land each time. Spell Pierce is a clunky include here since Abrupt Decay can't be countered and the deck wants to spend its mana proactively rather than hold up a counter. Keep the full removal suite (Burst Lightning, Reckless Rage) since this matchup is a race against efficient black removal and Thoughtseize.

This is a grindy matchup where their Eddymurk Crab and Hearth Elemental demand bigger answers than our cheap burn provides, so Scorching Shot comes in to cleanly kill their 4/5s and 5/5s with its 5 damage. Quantum Riddler gives us a late-game card advantage engine and a reasonably sized flying blocker against Stormwing Entity and Sunderflock. Boomerang Basics is a weak tempo play here since bouncing their creatures just lets them recast Hearth Elemental's Adventure side for value, so it comes out. Keep Burst Lightning and Reckless Rage in to pressure their early creatures while they're tapped out from Sleight of Hand and Opt.

UBR wants to resolve Fable of the Mirror-Breaker and Indomitable Creativity into huge threats like Atraxa or Valgavoth, so Spell Pierce is excellent at taxing their key spells on the draw or disrupting their plan when they're tapped out. Scorching Shot's 5 damage is big enough to kill most things they cheat into play off Indomitable Creativity, including Stormwing Entity and smaller creatures, while Burst Lightning and Reckless Rage stay in for Fable tokens. Boomerang Basics is a worse tempo play here than hard disruption since it doesn't answer a resolved Atraxa/Valgavoth, and Monstrous Rage is too aggressive-combat focused against a deck full of removal and counters. The game plan shifts slightly toward disruption since they have more powerful top-end than us.