head to head
Neither is simply harder - they are hard in different places. BlazBlue: Calamity Trigger demands more reads; Call of Duty: Black Ops demands more variance.

Execution · Competitive PvP
Anime fighter debuting the Drive system and famously execution-heavy cast.

Execution · Competitive PvP
Cold War-era shooter pairing twitch multiplayer with the cult Zombies mode.
BlazBlue: Calamity Trigger leans Execution (Competitive PvP); Call of Duty: Black Ops leans Execution (Competitive PvP).
BlazBlue: Calamity Trigger leans a little harder on execution, though the gap is small.
BlazBlue: Calamity Trigger
Long anime combos and tight defensive inputs
Call of Duty: Black Ops
Gunfights hinge on aim and reaction speed
BlazBlue: Calamity Trigger leans clearly harder on reads.
BlazBlue: Calamity Trigger
Human opponents demand constant conditioning and adaptation
Call of Duty: Black Ops
Reading human opponents' positioning and timing
Call of Duty: Black Ops leans clearly harder on variance.
BlazBlue: Calamity Trigger
Negligible randomness in matches
Call of Duty: Black Ops
Spawns, care packages, zombies RNG
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
BlazBlue: Calamity Trigger
Frame data, drive mechanics, and matchup study
Call of Duty: Black Ops
Class builds, map control, zombies routing
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.