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
Shot timing and play selection against opponents adjusting to your tendencies.

Execution · Competitive PvP
Timing-based basketball execution layered over playbook knowledge and opponent prediction.
NBA 2K14 leans Execution (Competitive PvP); NBA 2K9 leans Execution (Competitive PvP).
NBA 2K9 leans a little harder on execution, though the gap is small.
NBA 2K14
Shot release timing and dribble chains gate scoring
NBA 2K9
Shot timing and stick handles set the ceiling
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
NBA 2K14
Online opponents counter your favourite plays
NBA 2K9
Online defenders bait passes and adapt to your sets
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
NBA 2K14
Shot RNG sways close possessions
NBA 2K9
Shot RNG and bounces add bounded noise
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
NBA 2K14
Playbook knowledge and roster management reward study
NBA 2K9
Playbooks, matchups and roster management are learnable systems
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.