head to head
Left 4 Dead 2 asks more than Mario Kart World, and the gap is optimization.

Execution · Practiced Mastery
Co-op zombie shooter with adaptive AI Director.

Execution · Twitch Chaos
Kart racing blending drift execution with item RNG and pack positioning.
Left 4 Dead 2 leans Execution (Practiced Mastery); Mario Kart World leans Execution (Twitch Chaos).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Left 4 Dead 2
Headshots under horde pressure need aim
Mario Kart World
Drift charging, rail grinding and shortcut precision reward hands
Mario Kart World leans a little harder on reads, though the gap is small.
Left 4 Dead 2
Versus special-infected ambushes have reads
Mario Kart World
Human racers bait items and contest lines in knockouts
Mario Kart World leans a little harder on variance, though the gap is small.
Left 4 Dead 2
AI Director randomizes spawns and items
Mario Kart World
Item rolls and rubber-banding scramble any single race
Left 4 Dead 2 leans clearly harder on optimization.
Left 4 Dead 2
Route knowledge and weapon picks solvable
Mario Kart World
Course knowledge, shortcuts and item management converge with study
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.