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
An open-city sequel deepening freeflow combat and predator gadget play.

Optimization · Practiced Mastery
An open-world action game where hacking the city's infrastructure is your main weapon.
Batman: Arkham City leans Execution (Practiced Mastery); Watch Dogs leans Optimization (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Batman: Arkham City
Combo chains and counters need timing.
Watch Dogs
Cover shooting and driving at modest difficulty
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Batman: Arkham City
Enemies scripted, not adaptive.
Watch Dogs
Online invasions add a small human element
Watch Dogs leans a little harder on variance, though the gap is small.
Batman: Arkham City
Fixed encounters and challenges.
Watch Dogs
Guard placements are knowable on approach
Watch Dogs leans a little harder on optimization, though the gap is small.
Batman: Arkham City
Gadget combos and challenge maps learnable.
Watch Dogs
Hacking chains and camera routes make stealth solvable
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.