head to head
Rocket League asks more than Mario Tennis Aces, and the gap is execution.

Execution · Competitive PvP
Arcade tennis with timing-based PvP mind games.

Execution · Pure Mechanics
Mechanical car-soccer where execution is the ceiling.
Mario Tennis Aces leans Execution (Competitive PvP); Rocket League leans Execution (Pure Mechanics).
Rocket League leans clearly harder on execution.
Mario Tennis Aces
Shot timing, charge mechanics, footwork
Rocket League
Aerials, flicks, dribbles, pure mechanical ceiling
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Mario Tennis Aces
Online tennis demands reading opponent placement
Rocket League
Rotations and 50-50 reads against humans
Mario Tennis Aces leans a little harder on variance, though the gap is small.
Mario Tennis Aces
Mostly deterministic ball physics
Rocket League
Almost deterministic physics
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Mario Tennis Aces
Character matchups and tech routes
Rocket League
Training routines, rotation theory
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.