head to head
Super Smash Bros. Melee asks more than Mortal Kombat: Deception, and the gap is execution.

Execution · Competitive PvP
The Deadly Alliance follow-up adding combo breakers, death traps, and online play.

Execution · Competitive PvP
A platform fighter with one of the highest execution ceilings in any competitive game, layered on top of deep human reads.
Mortal Kombat: Deception leans Execution (Competitive PvP); Super Smash Bros. Melee leans Execution (Competitive PvP).
Super Smash Bros. Melee leans clearly harder on execution.
Mortal Kombat: Deception
Style strings plus stage-hazard spacing demand control
Super Smash Bros. Melee
Wavedashing, L-cancels, and tech-chasing set an extreme physical ceiling
Super Smash Bros. Melee leans clearly harder on reads.
Mortal Kombat: Deception
Human opponents bait death traps and breakers
Super Smash Bros. Melee
Reading DI choices and opponent adaptive habits is constant and non-convergent
Super Smash Bros. Melee leans a little harder on variance, though the gap is small.
Mortal Kombat: Deception
Deterministic outside known stage hazards
Super Smash Bros. Melee
Stage hazard RNG and spawn positions add marginal chaos
Super Smash Bros. Melee leans a little harder on optimization, though the gap is small.
Mortal Kombat: Deception
Combo routes and hazard positioning are lab work
Super Smash Bros. Melee
Character matchup tiers and optimal movement routing are deeply studied
A matching score does not mean a matching test. Two games can both sit at 10 on execution and demand completely different things of you - which is why the reasoning above matters more than the number beside it.