head to head
Counter-Strike: Global Offensive asks more than Halo 2: Anniversary, and the gap is execution.

Execution · Competitive PvP
Definitive competitive tactical FPS balancing aim mastery with team strategy.

Execution · Competitive PvP
Tests arena-shooter aim and map-control prediction against human lobbies.
Counter-Strike: Global Offensive leans Execution (Competitive PvP); Halo 2: Anniversary leans Execution (Competitive PvP).
Counter-Strike: Global Offensive leans clearly harder on execution.
Counter-Strike: Global Offensive
Spray control and flick precision at the top
Halo 2: Anniversary
Aim, grenades and movement decide every multiplayer duel
Counter-Strike: Global Offensive leans a little harder on reads, though the gap is small.
Counter-Strike: Global Offensive
Anti-stratting and mid-round adaptation
Halo 2: Anniversary
Predicting human positioning and power-weapon pushes is constant
Counter-Strike: Global Offensive leans a little harder on variance, though the gap is small.
Counter-Strike: Global Offensive
Information hidden until contact
Halo 2: Anniversary
Static spawns and timers leave little true randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Counter-Strike: Global Offensive
Utility lineups, economy, and default strats
Halo 2: Anniversary
Weapon timers, map control and campaign routes are learnable systems
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.