head to head
Splinter Cell: Chaos Theory asks more than Portal 2, and the gap is variance.

Optimization · Pure Optimization
A first-person puzzle game where seeing the solution is the whole skill.

Optimization · Pure Optimization
Engineering silent passages through layered guard awareness systems using body-stacking and sound tools.
Portal 2 leans Optimization (Pure Optimization); Splinter Cell: Chaos Theory leans Optimization (Pure Optimization).
Splinter Cell: Chaos Theory leans clearly harder on execution.
Portal 2
Portal placement requires some precision but timing is lenient.
Splinter Cell: Chaos Theory
Rappel aim, hand-over-hand movement, and knockouts require care
Splinter Cell: Chaos Theory leans a little harder on reads, though the gap is small.
Portal 2
No opponent; puzzles are static.
Splinter Cell: Chaos Theory
Guards talk and investigate on scripted awareness trees
Splinter Cell: Chaos Theory leans clearly harder on variance.
Portal 2
Puzzles are deterministic with no randomness.
Splinter Cell: Chaos Theory
Conversation triggers and item locations hold some first-run uncertainty
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Portal 2
Solving the puzzle's logic IS the entire game.
Splinter Cell: Chaos Theory
Sound-state management and multi-approach routing are the core skill
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.