head to head
Halo: Combat Evolved asks more than Red Dead Redemption 2, and the gap is execution.

Execution · Practiced Mastery
The console FPS landmark that introduced Master Chief and the ring world.

Execution · Practiced Mastery
A cinematic open-world western leaning on shooting feel and atmosphere.
Halo: Combat Evolved leans Execution (Practiced Mastery); Red Dead Redemption 2 leans Execution (Practiced Mastery).
Halo: Combat Evolved leans clearly harder on execution.
Halo: Combat Evolved
Aim, grenade timing, and vehicle control
Red Dead Redemption 2
Gunplay and Dead Eye reward aim and timing.
Halo: Combat Evolved leans clearly harder on reads.
Halo: Combat Evolved
Multiplayer duels reward reading humans
Red Dead Redemption 2
Enemies use scripted AI patterns, not adaptation.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Halo: Combat Evolved
Covenant AI varies tactics slightly
Red Dead Redemption 2
Some hunting and weather randomness, lightly hidden.
Halo: Combat Evolved leans a little harder on optimization, though the gap is small.
Halo: Combat Evolved
Weapon sandbox knowledge and encounter routing
Red Dead Redemption 2
Loadouts and routes solvable but loose.
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.