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
Mechanical football skill plus constant prediction of a human opponent's tendencies.

Execution · Competitive PvP
The peak-era Konami football game prized for weighty, skill-driven match play.
FIFA 17 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 17
Dribbling, shooting and defending inputs decide individual duels
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 17
Human opponents online keep shifting attacking and defending habits
Pro Evolution Soccer 6
Versus matches are constant feint and positioning prediction
FIFA 17 leans a little harder on variance, though the gap is small.
FIFA 17
Bounces, deflections and finishing RNG swing tight matches
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 17
Squad chemistry, formations and meta mechanics are studied layers
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.