head to head
NBA 2K16 asks more than FIFA 99, and the gap is optimization.

Execution · Competitive PvP
Late-90s arcade football execution with couch-versus prediction and bouncy luck.

Execution · Competitive PvP
Shot timing and play-calling against opponents who scheme around your habits.
FIFA 99 leans Execution (Competitive PvP); NBA 2K16 leans Execution (Competitive PvP).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
FIFA 99
Quick passing and shot timing in arcade-leaning football
NBA 2K16
Shot-stick timing and dribble moves gate every possession
NBA 2K16 leans a little harder on reads, though the gap is small.
FIFA 99
Couch opponents can be conditioned and baited
NBA 2K16
Online opponents adjust defensive schemes against your tendencies
FIFA 99 leans a little harder on variance, though the gap is small.
FIFA 99
Era physics produce regular fluke goals
NBA 2K16
Shot RNG and card packs add bounded randomness
NBA 2K16 leans clearly harder on optimization.
FIFA 99
Simple formations and known exploit angles map fast
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.