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

Execution · Twitch Chaos
A kart racer testing drift execution under item-roll variance.

Execution · Twitch Chaos
Co-op zombie shooter whose AI Director reshuffles every run to keep teams honest.
Chocobo Racing leans Execution (Twitch Chaos); Left 4 Dead leans Execution (Twitch Chaos).
Left 4 Dead leans a little harder on execution, though the gap is small.
Chocobo Racing
Drift timing and item dodges decide close finishes
Left 4 Dead
Headshots, melee shoves, and special-infected reaction time
Chocobo Racing leans a little harder on reads, though the gap is small.
Chocobo Racing
Two-player races add light human prediction
Left 4 Dead
Versus mode adds human ambush mindgames
Left 4 Dead leans a little harder on variance, though the gap is small.
Chocobo Racing
Item rolls swing race outcomes kart-style
Left 4 Dead
AI Director randomizes hordes, items, and specials
Left 4 Dead leans a little harder on optimization, though the gap is small.
Chocobo Racing
Ability picks and track shortcuts reward study
Left 4 Dead
Team spacing, route choice, and resource discipline
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.