head to head
Call of Duty: Modern Warfare 2 asks more than Celebrity Deathmatch, and the gap is execution.

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

Execution · Competitive PvP
A shallow novelty wrestler testing little beyond basic timing and weapon grabs.
Call of Duty: Modern Warfare 2 leans Execution (Competitive PvP); Celebrity Deathmatch leans Execution (Competitive PvP).
Call of Duty: Modern Warfare 2 leans clearly harder on execution.
Call of Duty: Modern Warfare 2
Fast time-to-kill rewards raw aim and reflex
Celebrity Deathmatch
Button timing wins matches but the ceiling is low
Call of Duty: Modern Warfare 2 leans clearly harder on reads.
Call of Duty: Modern Warfare 2
Outguessing human rotations and flanks
Celebrity Deathmatch
A couch opponent can be conditioned, shallowly
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
Celebrity Deathmatch
Random weapon drops shake up the ring
Call of Duty: Modern Warfare 2 leans clearly harder on optimization.
Call of Duty: Modern Warfare 2
Killstreak economy, loadout and map knowledge
Celebrity Deathmatch
Learning each celebrity's finisher exhausts the depth fast
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.