head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Execution · Competitive PvP
Stick skills and finishing wrapped around reading a human opponent's tendencies.

Execution · Competitive PvP
The peak-era Konami football game prized for weighty, skill-driven match play.
FIFA Soccer 09 leans Execution (Competitive PvP); Pro Evolution Soccer 6 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.
FIFA Soccer 09
Dribbling, timed tackles and finishing demand precise inputs
Pro Evolution Soccer 6
First touch, through balls, and dribbles demand precise control
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
FIFA Soccer 09
Human opponents shift tactics and exploit your habits mid-match
Pro Evolution Soccer 6
Versus matches are constant feint and positioning prediction
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
FIFA Soccer 09
Rebounds and referee moments add minor randomness
Pro Evolution Soccer 6
Deflections and keeper spills add light randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
FIFA Soccer 09
Squad selection and tactical setups are a solvable layer
Pro Evolution Soccer 6
Formations and player roles are studyable
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.