head to head
SoulCalibur III asks more than Top Spin 4, and the gap is reads.

Execution · Competitive PvP
Weapon-based dueling testing spacing execution and mixup prediction against humans.

Execution · Pure Mechanics
A simulation tennis game built around precise shot-timing rallies.
SoulCalibur III leans Execution (Competitive PvP); Top Spin 4 leans Execution (Pure Mechanics).
Top Spin 4 leans a little harder on execution, though the gap is small.
SoulCalibur III
Spacing, movement and just-frame timing demand real hands
Top Spin 4
Shot timing meter decides every rally
SoulCalibur III leans clearly harder on reads.
SoulCalibur III
Versus humans, conditioning and throw-mixup guessing decides rounds
Top Spin 4
Human PvP rewards anticipating placement habits
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
SoulCalibur III
Deterministic combat with nothing hidden
Top Spin 4
Almost no randomness in ball physics
SoulCalibur III leans a little harder on optimization, though the gap is small.
SoulCalibur III
Frame data, matchup study and stage knowledge run deep
Top Spin 4
Player builds and court tactics are learnable
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.