head to head
Gears of War 3 asks more than Grand Theft Auto: San Andreas, and the gap is reads.

Execution · Practiced Mastery
The trilogy capper with the series' most polished competitive multiplayer.

Optimization · Practiced Mastery
A sprawling open-world crime epic with RPG-style character stats across a whole state.
Gears of War 3 leans Execution (Practiced Mastery); Grand Theft Auto: San Andreas leans Optimization (Practiced Mastery).
Gears of War 3 leans clearly harder on execution.
Gears of War 3
Refined wallbounce and gnasher precision dominate versus
Grand Theft Auto: San Andreas
Flying school and drive-bys need decent hands
Gears of War 3 leans clearly harder on reads.
Gears of War 3
Reading human rotations and bait plays matters
Grand Theft Auto: San Andreas
Gang AI is scripted, never adaptive
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Gears of War 3
Horde waves vary slightly
Grand Theft Auto: San Andreas
Territory wars and traffic add light randomness
Grand Theft Auto: San Andreas leans a little harder on optimization, though the gap is small.
Gears of War 3
Map spawns and loadout meta are mappable
Grand Theft Auto: San Andreas
Stats, gym, weapon skill, and routes reward systematic play
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.