head to head
Neither is simply harder - they are hard in different places. NFL Head Coach 09 demands more reads; Portal 2 demands more execution.

Optimization · Pure Optimization
An NFL management sim about roster building, scouting and game planning.

Optimization · Pure Optimization
A first-person puzzle game where seeing the solution is the whole skill.
NFL Head Coach 09 leans Optimization (Pure Optimization); Portal 2 leans Optimization (Pure Optimization).
Portal 2 leans clearly harder on execution.
NFL Head Coach 09
No on-field input; pure management interface
Portal 2
Portal placement requires some precision but timing is lenient.
NFL Head Coach 09 leans clearly harder on reads.
NFL Head Coach 09
AI opponents scripted; light playcall prediction
Portal 2
No opponent; puzzles are static.
NFL Head Coach 09 leans clearly harder on variance.
NFL Head Coach 09
Draft prospects, injuries and game sims carry hidden uncertainty
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.
NFL Head Coach 09
Roster building, scouting and game planning are the whole game
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.