head to head
Call of Duty: Black Ops asks more than Rugby World Cup 2015, and the gap is execution.

Execution · Competitive PvP
Cold War-era shooter pairing twitch multiplayer with the cult Zombies mode.

Execution · Competitive PvP
A rugby simulation testing input timing and tactical play against opponents.
Call of Duty: Black Ops leans Execution (Competitive PvP); Rugby World Cup 2015 leans Execution (Competitive PvP).
Call of Duty: Black Ops leans clearly harder on execution.
Call of Duty: Black Ops
Gunfights hinge on aim and reaction speed
Rugby World Cup 2015
Timing passes, tackles, and kicks needs consistent inputs
Call of Duty: Black Ops leans a little harder on reads, though the gap is small.
Call of Duty: Black Ops
Reading human opponents' positioning and timing
Rugby World Cup 2015
Human opponents can be read in multiplayer matches
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Call of Duty: Black Ops
Spawns, care packages, zombies RNG
Rugby World Cup 2015
Ball bounces and AI add some unpredictability
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Call of Duty: Black Ops
Class builds, map control, zombies routing
Rugby World Cup 2015
Set plays, team selection, and tactics form a systems layer
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.