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

Execution · Grand Arena
A football sim where reading opponents and precise execution both decide matches.

Execution · Competitive PvP
Fighting-game execution and opponent prediction across an enormous, loosely balanced roster.
FIFA 20 leans Execution (Grand Arena); Mortal Kombat: Armageddon 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.
FIFA 20
precise passing, dribbling, and shot timing
Mortal Kombat: Armageddon
Combo strings and kombat timing decide exchanges
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
FIFA 20
reading human opponent tactics live
Mortal Kombat: Armageddon
Versus humans, baiting and punishing habits is the meta
FIFA 20 leans a little harder on variance, though the gap is small.
FIFA 20
minor ball physics and injury randomness
Mortal Kombat: Armageddon
No hidden information once movesets are known
FIFA 20 leans a little harder on optimization, though the gap is small.
FIFA 20
formations and player builds solvable
Mortal Kombat: Armageddon
A 62-character roster of matchup knowledge to internalise
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.