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
Shot timing and play-calling against opponents who scheme around your habits.

Execution · Practiced Mastery
Stick-skill execution and opponent habit-reading over a solvable hockey meta.
NBA 2K16 leans Execution (Competitive PvP); NHL 23 leans Execution (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
NBA 2K16
Shot-stick timing and dribble moves gate every possession
NHL 23
Skill-stick dekes and shot timing carry possession play
NBA 2K16 leans a little harder on reads, though the gap is small.
NBA 2K16
Online opponents adjust defensive schemes against your tendencies
NHL 23
Online opponents reward reading defensive structure habits
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
NBA 2K16
Shot RNG and card packs add bounded randomness
NHL 23
Bounces, deflections and goalie AI add noise
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
NBA 2K16
Playbooks, rotations and roster building reward deep study
NHL 23
Meta builds, line chemistry and set plays are studyable
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.