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
Stick-controlled tennis testing swing timing and percentage shot selection.

Execution · Practiced Mastery
Aggressive circuit racing testing car control over memorisable tracks and braking points.
Grand Slam Tennis 2 leans Execution (Practiced Mastery); Race Driver: Grid 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.
Grand Slam Tennis 2
Total Racket Control stick swings demand precise timing
Race Driver: Grid
Aggressive wheel-to-wheel car control is the core demand
Grand Slam Tennis 2 leans a little harder on reads, though the gap is small.
Grand Slam Tennis 2
Versus humans, disguising shot placement is genuine prediction
Race Driver: Grid
Online racing adds light opponent positioning awareness
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Slam Tennis 2
Ball physics are nearly deterministic
Race Driver: Grid
Damage outcomes add slight unpredictability to contact
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Slam Tennis 2
Shot selection and court positioning follow learnable percentages
Race Driver: Grid
Braking points, lines and flashback management are learnable
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.