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 · Pure Mechanics
A time-trial racer where flawless inputs over fixed tracks are everything.

Execution · Practiced Mastery
Pure time-trial racing testing relentless execution of an ever-more-optimised line.
Trackmania leans Execution (Pure Mechanics); TrackMania United Forever leans Execution (Practiced Mastery).
Trackmania leans a little harder on execution, though the gap is small.
Trackmania
Pure input precision over deterministic tracks defines everything.
TrackMania United Forever
Frame-perfect lines over hundreds of restarts are everything
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Trackmania
No opponent; ghost runs only.
TrackMania United Forever
Time trials against ghosts - no one adapts to you
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Trackmania
Tracks are deterministic with zero randomness.
TrackMania United Forever
Deterministic physics with literally nothing hidden
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Trackmania
Line optimization and shortcut discovery matter heavily.
TrackMania United Forever
Finding the theoretical fastest line is the meta-game
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.