head to head
Old School RuneScape asks more than Portal 2, and the gap is variance.

Optimization · Pure Optimization
An MMO solved through efficiency routing with niche tick-execution skill ceilings.

Optimization · Pure Optimization
A first-person puzzle game where seeing the solution is the whole skill.
Old School RuneScape leans Optimization (Pure Optimization); Portal 2 leans Optimization (Pure Optimization).
Old School RuneScape leans a little harder on execution, though the gap is small.
Old School RuneScape
Tick-perfect inputs in high-end PvM
Portal 2
Portal placement requires some precision but timing is lenient.
Old School RuneScape leans clearly harder on reads.
Old School RuneScape
PvP wilderness has genuine read element
Portal 2
No opponent; puzzles are static.
Old School RuneScape leans clearly harder on variance.
Old School RuneScape
Drop rates and clue RNG drive economy
Portal 2
Puzzles are deterministic with no randomness.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Old School RuneScape
Efficiency, routing, and GP/hour fully theorycrafted
Portal 2
Solving the puzzle's logic IS the entire game.
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.