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
Football sim testing execution and opponent reading under a studied tactical meta.

Reads · Competitive PvP
Modern Worms with crafting and vehicles, keeping the classic turn-based destructible-terrain warfare.
FIFA 21 leans Execution (Competitive PvP); Worms W.M.D leans Reads (Competitive PvP).
FIFA 21 leans a little harder on execution, though the gap is small.
FIFA 21
Skill moves and finishing mechanics demand practiced hands
Worms W.M.D
Shot arcs, rope swings and vehicle control demand precision
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
FIFA 21
Outguessing a human's defensive shape and attacking patterns is central
Worms W.M.D
Multiplayer turns hinge on out-guessing rival worm placement
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
FIFA 21
Deflections, finishing RNG and pack luck colour outcomes
Worms W.M.D
Wind, crates and random terrain reshape options
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
FIFA 21
Meta formations, custom tactics and squad building are studied deeply
Worms W.M.D
Crafting and weapon budgeting reward planned turns
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.