head to head
Splatoon 2 asks more than Red Dead Redemption 2, and the gap is reads.

Execution · Practiced Mastery
A cinematic open-world western leaning on shooting feel and atmosphere.

Execution · Practiced Mastery
A team shooter where aim and positioning against human opponents controls the map.
Red Dead Redemption 2 leans Execution (Practiced Mastery); Splatoon 2 leans Execution (Practiced Mastery).
Splatoon 2 leans clearly harder on execution.
Red Dead Redemption 2
Gunplay and Dead Eye reward aim and timing.
Splatoon 2
aim and movement decide ink battles
Splatoon 2 leans clearly harder on reads.
Red Dead Redemption 2
Enemies use scripted AI patterns, not adaptation.
Splatoon 2
predicting human opponent positioning
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Red Dead Redemption 2
Some hunting and weather randomness, lightly hidden.
Splatoon 2
weapon and map rotation randomness
Splatoon 2 leans clearly harder on optimization.
Red Dead Redemption 2
Loadouts and routes solvable but loose.
Splatoon 2
loadout and turf strategy 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.