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
An arcade soccer game testing ball control and prediction against opponents.

Execution · Competitive PvP
Execution on the ball plus constant prediction of the other player's shape.
International Superstar Soccer 2 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.
International Superstar Soccer 2
Passing, shooting and dribbling timing decides plays
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.
International Superstar Soccer 2
Human opponents juke and feint, demanding prediction
Pro Evolution Soccer 2009
Online and couch opponents adjust tactics against you
International Superstar Soccer 2 leans a little harder on variance, though the gap is small.
International Superstar Soccer 2
Ball physics and deflections add some chaos
Pro Evolution Soccer 2009
Ricochets and keeper parries add small randomness
International Superstar Soccer 2 leans a little harder on optimization, though the gap is small.
International Superstar Soccer 2
Formations, tactics and build-up play matter underneath
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.