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 · Grand Arena
Frame-perfect execution fused with constant prediction of an adapting human opponent.

Reads · Grand Arena
A neutral-focused fighter where managing the GRD gauge against an adapting opponent creates a constant strategic tug-of-war.
Ultra Street Fighter IV leans Execution (Grand Arena); Under Night In-Birth II Sys:Celes leans Reads (Grand Arena).
Ultra Street Fighter IV leans a little harder on execution, though the gap is small.
Ultra Street Fighter IV
One-frame links and FADC timing set a brutal hands ceiling
Under Night In-Birth II Sys:Celes
GRD-boosted combos and precise Chain Shift timing demand real execution
Under Night In-Birth II Sys:Celes leans a little harder on reads, though the gap is small.
Ultra Street Fighter IV
Footsies and conditioning the human opponent is the core duel
Under Night In-Birth II Sys:Celes
GRD tug-of-war with a human opponent is persistently adaptive
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Ultra Street Fighter IV
Almost nothing hidden once both characters are known
Under Night In-Birth II Sys:Celes
No RNG; GRD state is visible information
Under Night In-Birth II Sys:Celes leans a little harder on optimization, though the gap is small.
Ultra Street Fighter IV
Frame data, matchups and option-selects form deep studied theory
Under Night In-Birth II Sys:Celes
GRD management theory and optimal punish routing are well-documented
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.