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
Blockbuster 2009 sequel famous for killstreak chains and frantic multiplayer.

Execution · Grand Arena
A football sim testing stick execution, play-call reads, and playbook optimisation against opponents.
Call of Duty: Modern Warfare 2 leans Execution (Competitive PvP); NFL 2K1 leans Execution (Grand Arena).
Call of Duty: Modern Warfare 2 leans a little harder on execution, though the gap is small.
Call of Duty: Modern Warfare 2
Fast time-to-kill rewards raw aim and reflex
NFL 2K1
Precise stick control on passes and jukes matters
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Call of Duty: Modern Warfare 2
Outguessing human rotations and flanks
NFL 2K1
Reading a human opponent's play-calls is central
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Call of Duty: Modern Warfare 2
Spawn flips and killstreak randomness
NFL 2K1
Fumbles and catch outcomes add measured chaos
NFL 2K1 leans a little harder on optimization, though the gap is small.
Call of Duty: Modern Warfare 2
Killstreak economy, loadout and map knowledge
NFL 2K1
Playbook knowledge and matchup exploitation 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.