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 · Practiced Mastery
A gritty WWII Call of Duty that introduced the Zombies mode.

Execution · Practiced Mastery
A licensed soccer simulation following the Champions League tournament.
Call of Duty: World at War leans Execution (Practiced Mastery); UEFA Champions League 1999/2000 leans Execution (Practiced Mastery).
Call of Duty: World at War leans a little harder on execution, though the gap is small.
Call of Duty: World at War
Twitch gunfights in fast multiplayer lobbies
UEFA Champions League 1999/2000
passing and shooting require timing precision
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Call of Duty: World at War
Human opponents reward positioning prediction
UEFA Champions League 1999/2000
human opponents add some adaptive play
Call of Duty: World at War leans a little harder on variance, though the gap is small.
Call of Duty: World at War
Random lobbies, spawns, and zombie waves
UEFA Champions League 1999/2000
ball physics create minor unpredictability
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Call of Duty: World at War
Perk loadouts and map control are learnable
UEFA Champions League 1999/2000
tactics and formation choices matter
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.