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 · Competitive PvP
A baseball sim testing swing timing and the pitcher-batter guessing duel atop roster strategy.
Call of Duty: Modern Warfare 2 leans Execution (Competitive PvP); MLB 15: The Show leans Execution (Competitive PvP).
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
MLB 15: The Show
Pitch timing and swing precision set the physical ceiling
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
MLB 15: The Show
Guessing a human pitcher's sequence is classic mind-gaming
MLB 15: The Show leans a little harder on variance, though the gap is small.
Call of Duty: Modern Warfare 2
Spawn flips and killstreak randomness
MLB 15: The Show
Batted-ball physics and simulation rolls add real randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Call of Duty: Modern Warfare 2
Killstreak economy, loadout and map knowledge
MLB 15: The Show
Roster building, matchups, and situational strategy run underneath
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.