head to head
Blur asks more than Half-Life 2, and the gap is variance.

Execution · Pure Mechanics
Arcade racing with Mario Kart-style power-ups bolted onto licensed cars.

Execution · Pure Mechanics
Landmark FPS built on physics puzzles and tight gunplay.
Blur leans Execution (Pure Mechanics); Half-Life 2 leans Execution (Pure Mechanics).
Blur leans a little harder on execution, though the gap is small.
Blur
Racing lines and dodging shots demand car control
Half-Life 2
Gravity gun and shooting demand precision.
Blur leans clearly harder on reads.
Blur
Human racers bait and time power-ups against you
Half-Life 2
Combine AI scripted, non-adaptive.
Blur leans clearly harder on variance.
Blur
Power-up pickups and incoming attacks add chaos
Half-Life 2
Almost no randomness.
Blur leans a little harder on optimization, though the gap is small.
Blur
Track knowledge and pickup routes are learnable
Half-Life 2
Linear progression with no builds.
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.