head to head
Neither is simply harder - they are hard in different places. Champions World Class Soccer demands more reads; Grand Theft Auto: San Andreas demands more optimization.

Execution · Practiced Mastery
A basic arcade soccer game testing input timing and simple positioning.

Optimization · Practiced Mastery
A sprawling open-world crime epic with RPG-style character stats across a whole state.
Champions World Class Soccer leans Execution (Practiced Mastery); Grand Theft Auto: San Andreas leans Optimization (Practiced Mastery).
Champions World Class Soccer leans clearly harder on execution.
Champions World Class Soccer
Passing, shooting and tackling timing carry every play
Grand Theft Auto: San Andreas
Flying school and drive-bys need decent hands
Champions World Class Soccer leans clearly harder on reads.
Champions World Class Soccer
Two-player mode lets you predict a human opponent
Grand Theft Auto: San Andreas
Gang AI is scripted, never adaptive
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Champions World Class Soccer
Little randomness once team ratings are known
Grand Theft Auto: San Andreas
Territory wars and traffic add light randomness
Grand Theft Auto: San Andreas leans clearly harder on optimization.
Champions World Class Soccer
Formation choice and team selection give a known edge
Grand Theft Auto: San Andreas
Stats, gym, weapon skill, and routes reward systematic play
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.