head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is execution, and it is a single point.

Execution · Grand Arena
A high-execution fighter where one-frame links and opponent modelling separate competitors.

Execution · Grand Arena
A tag-team crossover fighter pitting Street Fighter's cast against Tekken's under Capcom rules.
Street Fighter IV leans Execution (Grand Arena); Street Fighter X Tekken leans Execution (Grand Arena).
Street Fighter IV leans a little harder on execution, though the gap is small.
Street Fighter IV
One-frame links and FADC combos demand extreme motor precision
Street Fighter X Tekken
Tag combos and juggle timing demand practiced hands
Street Fighter IV leans a little harder on reads, though the gap is small.
Street Fighter IV
Reading opponent habits, wake-up patterns, and adaptations is the meta
Street Fighter X Tekken
Human mixups and tag baits require adaptation
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Street Fighter IV
Virtually no RNG; every outcome is skill-driven
Street Fighter X Tekken
Deterministic aside from negligible elements
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Street Fighter IV
Frame data, punish windows, and matchup charts are deeply studied
Street Fighter X Tekken
Gem loadouts and team synergy add a builder layer
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.