Shared Discovery 
Sorcery
As an additional cost to cast this spell, tap four untapped creatures you control.
Draw three cards.
click a line to search just that ability, click more to combine them
Cards that do something similar expected a card that isn't here?
Reports become test cases the matcher is graded against before an update ships. Delvefall isn't a chatbot guessing, it compares the printed rules text of every card with plain math, and examples like yours decide which differences should count.
Nullmage Shepherd 87%
$1.02#5973
"Tap four untapped creatures you control: Destroy target artifact or enchantment."
Burn at the Stake 85%
$0.99#11290
"As an additional cost to cast this spell, tap any number of untapped creatures you control."
Explosive Singularity 81%
$0.55#9911
"As an additional cost to cast this spell, you may tap any number of untapped creatures you control. This spell costs {1} less to cast for each creature tapped this way."
Honeymoon Hearse 80%
$0.15#22243
"Tap two untapped creatures you control: This Vehicle becomes an artifact creature until end of turn."