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

Execution · Competitive PvP
Play-calling mind games against a human layered over stick execution and roster planning.

Execution · Competitive PvP
Shot timing and play-calling against opponents who scheme around your habits.
All-Pro Football 2K8 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.
All-Pro Football 2K8
Stick skills on passes, jukes and tackles decide individual plays
NBA 2K16
Shot-stick timing and dribble moves gate every possession
All-Pro Football 2K8 leans a little harder on reads, though the gap is small.
All-Pro Football 2K8
Play-calling against a human is a genuine prediction duel
NBA 2K16
Online opponents adjust defensive schemes against your tendencies
All-Pro Football 2K8 leans a little harder on variance, though the gap is small.
All-Pro Football 2K8
Catches, fumbles and matchup rolls add per-play 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.
All-Pro Football 2K8
Roster construction and playbook knowledge set the floor
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.