head to head
Tony Hawk's Underground 2 asks more than Grand Theft Auto: San Andreas, and the gap is execution.

Optimization · Practiced Mastery
A sprawling open-world crime epic with RPG-style character stats across a whole state.

Execution · Practiced Mastery
Combo execution layered over solving each park's optimal scoring line.
Grand Theft Auto: San Andreas leans Optimization (Practiced Mastery); Tony Hawk's Underground 2 leans Execution (Practiced Mastery).
Tony Hawk's Underground 2 leans clearly harder on execution.
Grand Theft Auto: San Andreas
Flying school and drive-bys need decent hands
Tony Hawk's Underground 2
Combo timing, balance meters and manuals demand practiced hands
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto: San Andreas
Gang AI is scripted, never adaptive
Tony Hawk's Underground 2
No opponent adapts; score attack is solo
Grand Theft Auto: San Andreas leans a little harder on variance, though the gap is small.
Grand Theft Auto: San Andreas
Territory wars and traffic add light randomness
Tony Hawk's Underground 2
Maps and goals are fixed and fully knowable
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto: San Andreas
Stats, gym, weapon skill, and routes reward systematic play
Tony Hawk's Underground 2
Finding the highest-scoring line through each park is solvable
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.