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
Definitive competitive tactical FPS balancing aim mastery with team strategy.

Execution · Competitive PvP
Team-based WWII infantry shooter about holding and capturing map points.
Counter-Strike: Global Offensive leans Execution (Competitive PvP); Day of Defeat: Source leans Execution (Competitive PvP).
Counter-Strike: Global Offensive leans a little harder on execution, though the gap is small.
Counter-Strike: Global Offensive
Spray control and flick precision at the top
Day of Defeat: Source
Recoil control and snap aim decide most firefights
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
Day of Defeat: Source
Human squads shift pushes and holds unpredictably
Counter-Strike: Global Offensive leans a little harder on variance, though the gap is small.
Counter-Strike: Global Offensive
Information hidden until contact
Day of Defeat: Source
Known maps, minimal randomness beyond spawn waves
Counter-Strike: Global Offensive leans a little harder on optimization, though the gap is small.
Counter-Strike: Global Offensive
Utility lineups, economy, and default strats
Day of Defeat: Source
Class loadouts and lane control are quickly mapped
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.