head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is variance, and it is a single point.

Execution · Practiced Mastery
Columbia's sky-rail shooter wrapped in dimensional intrigue.

Execution · Practiced Mastery
A grittier crime story where weighty driving and gunplay carry the experience.
BioShock Infinite leans Execution (Practiced Mastery); Grand Theft Auto IV leans Execution (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
BioShock Infinite
Skyline traversal and aiming reward inputs.
Grand Theft Auto IV
Heavier driving and cover shooting reward control.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
BioShock Infinite
Enemies scripted in arena waves.
Grand Theft Auto IV
Scripted AI, no adaptive opponent modeling.
Grand Theft Auto IV leans a little harder on variance, though the gap is small.
BioShock Infinite
Loot drops mildly randomized.
Grand Theft Auto IV
Minor mission variance.
BioShock Infinite leans a little harder on optimization, though the gap is small.
BioShock Infinite
Gear, vigors, weapon picks straightforward.
Grand Theft Auto IV
Mission routing and weapon picks learnable.
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.