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 · Competitive PvP
The Dreamcast classic that defined weapons-based 3D fighting with fluid eight-way movement.

Execution · Competitive PvP
The classic 'dream match' team fighter widely held as KOF's most balanced competitive entry.
Soulcalibur leans Execution (Competitive PvP); The King of Fighters '98 leans Execution (Competitive PvP).
The King of Fighters '98 leans a little harder on execution, though the gap is small.
Soulcalibur
Eight-way run and precise spacing reward sharp movement hands.
The King of Fighters '98
Strict inputs, short hops, tight punishes
The King of Fighters '98 leans a little harder on reads, though the gap is small.
Soulcalibur
Mid-low-throw mixups and Guard Impact baits against adapting opponents.
The King of Fighters '98
Human opponents constantly adapt and condition you
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Soulcalibur
Fully deterministic; no hidden systems.
The King of Fighters '98
Near-fully visible game state
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Soulcalibur
Ring-out positioning and frame knowledge are deeply labbable.
The King of Fighters '98
Team order and matchup theory reward study
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.