head to head
Call of Duty: Modern Warfare 2 asks more than UEFA Euro 2008, and the gap is execution.

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

Execution · Competitive PvP
Stick-skill football execution with opponent prediction in versus play.
Call of Duty: Modern Warfare 2 leans Execution (Competitive PvP); UEFA Euro 2008 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
UEFA Euro 2008
Pass timing, dribbling and finishing decide matches
Call of Duty: Modern Warfare 2 leans clearly harder on reads.
Call of Duty: Modern Warfare 2
Outguessing human rotations and flanks
UEFA Euro 2008
Versus humans, baiting tackles and disguising attacks matters
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
UEFA Euro 2008
Bounces and deflections add football's usual noise
Call of Duty: Modern Warfare 2 leans a little harder on optimization, though the gap is small.
Call of Duty: Modern Warfare 2
Killstreak economy, loadout and map knowledge
UEFA Euro 2008
Formations and squad selection sit underneath
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.