head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is execution, and it is a single point.

Execution · Competitive PvP
Combined-arms multiplayer shooter famous for map-altering levolution moments and 64-player conquest.

Execution · Competitive PvP
Shot timing and play-calling against opponents who scheme around your habits.
Battlefield 4 leans Execution (Competitive PvP); NBA 2K16 leans Execution (Competitive PvP).
Battlefield 4 leans a little harder on execution, though the gap is small.
Battlefield 4
Gunplay, vehicle mastery, and movement under fire
NBA 2K16
Shot-stick timing and dribble moves gate every possession
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Battlefield 4
Human teams adapt to flanks and levolution chokes
NBA 2K16
Online opponents adjust defensive schemes against your tendencies
Battlefield 4 leans a little harder on variance, though the gap is small.
Battlefield 4
Map-altering events and spawns inject noise
NBA 2K16
Shot RNG and card packs add bounded randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Battlefield 4
Loadout tuning and objective rotation knowledge
NBA 2K16
Playbooks, rotations and roster building reward deep study
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.