head to head
Red Faction 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
Mars-mining rebellion FPS famous for letting you blast through the terrain itself.
Grand Theft Auto: San Andreas leans Optimization (Practiced Mastery); Red Faction leans Execution (Practiced Mastery).
Red Faction leans clearly harder on execution.
Grand Theft Auto: San Andreas
Flying school and drive-bys need decent hands
Red Faction
Classic FPS aim and movement carry the campaign.
Red Faction leans a little harder on reads, though the gap is small.
Grand Theft Auto: San Andreas
Gang AI is scripted, never adaptive
Red Faction
Scripted guards; multiplayer was a minor side mode.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto: San Andreas
Territory wars and traffic add light randomness
Red Faction
Unknown level layouts first time through.
Grand Theft Auto: San Andreas leans a little harder on optimization, though the gap is small.
Grand Theft Auto: San Andreas
Stats, gym, weapon skill, and routes reward systematic play
Red Faction
Geo-Mod tunneling and route knowledge open solvable shortcuts.
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.