head to head
Super Smash Bros. Melee asks more than Call of Duty: Modern Warfare 2, and the gap is reads.

Execution · Competitive PvP
Blockbuster 2009 sequel famous for killstreak chains and frantic multiplayer.

Execution · Competitive PvP
A platform fighter with one of the highest execution ceilings in any competitive game, layered on top of deep human reads.
Call of Duty: Modern Warfare 2 leans Execution (Competitive PvP); Super Smash Bros. Melee leans Execution (Competitive PvP).
Super Smash Bros. Melee leans clearly harder on execution.
Call of Duty: Modern Warfare 2
Fast time-to-kill rewards raw aim and reflex
Super Smash Bros. Melee
Wavedashing, L-cancels, and tech-chasing set an extreme physical ceiling
Super Smash Bros. Melee leans clearly harder on reads.
Call of Duty: Modern Warfare 2
Outguessing human rotations and flanks
Super Smash Bros. Melee
Reading DI choices and opponent adaptive habits is constant and non-convergent
Call of Duty: Modern Warfare 2 leans a little harder on variance, though the gap is small.
Call of Duty: Modern Warfare 2
Spawn flips and killstreak randomness
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.
Call of Duty: Modern Warfare 2
Killstreak economy, loadout and map knowledge
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.