head to head
SimCity 4 asks more than Cities: Skylines, and the gap is variance.

Optimization · Pure Optimization
A sandbox city builder that is pure traffic and zoning optimization.

Optimization · Pure Optimization
Optimizing regional economics and city services to sustain growth without collapsing your budget.
Cities: Skylines leans Optimization (Pure Optimization); SimCity 4 leans Optimization (Pure Optimization).
SimCity 4 leans a little harder on execution, though the gap is small.
Cities: Skylines
No reflex demands at all.
SimCity 4
Point-and-click placement; zero reflex requirement
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Cities: Skylines
No adaptive opponent exists in the sandbox.
SimCity 4
Solo sandbox with no adversarial pressure
SimCity 4 leans clearly harder on variance.
Cities: Skylines
Minor disaster events if enabled.
SimCity 4
Neighbor city interactions and demand curves add unpredictability
Cities: Skylines leans a little harder on optimization, though the gap is small.
Cities: Skylines
Traffic flow, zoning, and budgets are fully solvable.
SimCity 4
Budget, ordinances, and transport networks are the core puzzle
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.