head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Execution · Competitive PvP
The 3D fighting series opener where execution and human mind-games decide every round.

Execution · Competitive PvP
The classic 'dream match' team fighter widely held as KOF's most balanced competitive entry.
Tekken leans Execution (Competitive PvP); The King of Fighters '98 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.
Tekken
Frame-tight inputs, juggle combos, movement demand trained hands
The King of Fighters '98
Strict inputs, short hops, tight punishes
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Tekken
Human opponent adapts; throws, lows, sidesteps form mixup mind-games
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.
Tekken
No hidden info; only matchup unfamiliarity early on
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.
Tekken
Frame data, punishes, and combo routing are studyable systems
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.