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 · Competitive PvP
Timing-based rallies and human shot-prediction wrapped in party-court chaos.

Execution · Competitive PvP
Execution on the ball plus constant prediction of the other player's shape.
Mario Power Tennis leans Execution (Competitive PvP); Pro Evolution Soccer 2009 leans Execution (Competitive PvP).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Mario Power Tennis
Shot timing and court positioning decide rallies
Pro Evolution Soccer 2009
Close control and finishing windows demand stick precision
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Mario Power Tennis
Versus humans, baiting and outguessing shot placement matters
Pro Evolution Soccer 2009
Online and couch opponents adjust tactics against you
Mario Power Tennis leans a little harder on variance, though the gap is small.
Mario Power Tennis
Gimmick courts and items inject chaos into points
Pro Evolution Soccer 2009
Ricochets and keeper parries add small randomness
Pro Evolution Soccer 2009 leans a little harder on optimization, though the gap is small.
Mario Power Tennis
Character matchups and shot selection reward modest study
Pro Evolution Soccer 2009
Squad setup and tactical sliders reward preparation
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.