head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is optimization, and it is a single point.

Execution · Competitive PvP
A tactical shooter where precise gunplay against human opposition is the deciding skill.

Execution · Competitive PvP
Team-based WWII infantry shooter about holding and capturing map points.
Counter-Strike: Condition Zero leans Execution (Competitive PvP); Day of Defeat: Source leans Execution (Competitive PvP).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Counter-Strike: Condition Zero
aim and spray control decide duels
Day of Defeat: Source
Recoil control and snap aim decide most firefights
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Counter-Strike: Condition Zero
predicting human opponent positioning
Day of Defeat: Source
Human squads shift pushes and holds unpredictably
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Counter-Strike: Condition Zero
buy-round economy and drops vary slightly
Day of Defeat: Source
Known maps, minimal randomness beyond spawn waves
Counter-Strike: Condition Zero leans a little harder on optimization, though the gap is small.
Counter-Strike: Condition Zero
economy management and utility usage solvable
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.