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.

Optimization · Systems & Chaos
Tests assembling broken card synergies under randomised offers, run after run.

Optimization · Pure Optimization
The classic AD&D CRPG where party planning beats dice luck over time.
9 Kings leans Optimization (Systems & Chaos); Baldur's Gate leans Optimization (Pure Optimization).
Baldur's Gate leans a little harder on execution, though the gap is small.
9 Kings
Placing cards between auto-battles needs no dexterity
Baldur's Gate
Pause-and-play needs minimal dexterity.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
9 Kings
Rival kings follow fixed escalation, not adaptive minds
Baldur's Gate
Scripted encounters, no adaptation.
9 Kings leans a little harder on variance, though the gap is small.
9 Kings
Card offers and enemy king draws randomise each run
Baldur's Gate
AD&D dice rolls throughout.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
9 Kings
Stacking synergies into broken kingdom builds is the entire loop
Baldur's Gate
Party builds and encounter prep solvable.
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.