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

Execution · Practiced Mastery
343's debut pits Master Chief against the Didact with loadout-driven multiplayer.

Execution · Practiced Mastery
N64 spy FPS famed for gadget-heavy missions and bot-filled multiplayer.
Halo 4 leans Execution (Practiced Mastery); Perfect Dark 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.
Halo 4
Precision aim amid faster kill times
Perfect Dark
N64 manual aim and tight mission play
Halo 4 leans a little harder on reads, though the gap is small.
Halo 4
Human opponents in Infinity multiplayer
Perfect Dark
Multiplayer and clever sims add some human-style adaptation
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Halo 4
Ordnance drops randomise mid-match rewards
Perfect Dark
Mission scripting fixed once learned
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Halo 4
Loadout building and map control
Perfect Dark
Objective routing on harder difficulty tiers
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.