head to head
Call of Duty: Black Ops asks more than Def Jam Vendetta, and the gap is execution.

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

Execution · Competitive PvP
Wrestling-style timing duels with grapple prediction against human opponents.
Call of Duty: Black Ops leans Execution (Competitive PvP); Def Jam Vendetta 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
Def Jam Vendetta
Grapple timing and reversal windows demand sharp 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
Def Jam Vendetta
Human matches turn on predicting grapples versus strikes
Call of Duty: Black Ops leans clearly harder on variance.
Call of Duty: Black Ops
Spawns, care packages, zombies RNG
Def Jam Vendetta
Nothing hidden once movesets are learned
Call of Duty: Black Ops leans a little harder on optimization, though the gap is small.
Call of Duty: Black Ops
Class builds, map control, zombies routing
Def Jam Vendetta
Character move pools and reversal systems are mappable
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.