head to head
ISS Pro Evolution 2 asks more than Half-Life 2, and the gap is reads.

Execution · Pure Mechanics
Landmark FPS built on physics puzzles and tight gunplay.

Execution · Pure Mechanics
Classic football execution - touch, timing and finishing - with human mind-games on top.
Half-Life 2 leans Execution (Pure Mechanics); ISS Pro Evolution 2 leans Execution (Pure Mechanics).
ISS Pro Evolution 2 leans a little harder on execution, though the gap is small.
Half-Life 2
Gravity gun and shooting demand precision.
ISS Pro Evolution 2
First-touch control, through-ball timing and finishing decide matches
ISS Pro Evolution 2 leans clearly harder on reads.
Half-Life 2
Combine AI scripted, non-adaptive.
ISS Pro Evolution 2
Versus humans, baiting tackles and disguising passes matters
ISS Pro Evolution 2 leans a little harder on variance, though the gap is small.
Half-Life 2
Almost no randomness.
ISS Pro Evolution 2
Slight bounce and keeper randomness within a deterministic sim
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Half-Life 2
Linear progression with no builds.
ISS Pro Evolution 2
Formation and player-role knowledge gives a modest edge
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.