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
Cornering execution over memorisable circuits, with light prediction in wheel-to-wheel multiplayer.

Execution · Pure Mechanics
Drift execution and learned racing lines through destructible city tracks.
Grid 2 leans Execution (Practiced Mastery); Ridge Racer Unbounded leans Execution (Pure Mechanics).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Grid 2
Car control through corners is the entire moment-to-moment test
Ridge Racer Unbounded
Drift control and boost timing decide every race
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Grid 2
Online wheel-to-wheel adds light positional prediction
Ridge Racer Unbounded
Online rivals allow mild positional prediction
Ridge Racer Unbounded leans a little harder on variance, though the gap is small.
Grid 2
Tracks are fixed and fully visible
Ridge Racer Unbounded
Destruction chaos adds modest track noise
Grid 2 leans a little harder on optimization, though the gap is small.
Grid 2
Racing lines, braking points and car selection are studyable
Ridge Racer Unbounded
Learning racing lines and shortcut routes rewards 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.