head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is optimization, and it is a single point.

Execution · Practiced Mastery
Accessible car control amid demolition chaos rather than precision racing.

Execution · Practiced Mastery
Managing air meter and shortcut routes at speed on memorised tracks.
Dirt Showdown leans Execution (Practiced Mastery); Sonic Riders 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.
Dirt Showdown
Drifting, boosting and ramming need solid car control
Sonic Riders
Air management, drift timing and shortcuts demand practiced hands
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Dirt Showdown
Demolition modes reward predicting human movement a little
Sonic Riders
Versus humans there is mild positional jockeying
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Dirt Showdown
Crash physics and pack chaos add randomness
Sonic Riders
Item and turbulence placement adds light randomness
Sonic Riders leans a little harder on optimization, though the gap is small.
Dirt Showdown
Event types and boost routes are quickly learnable
Sonic Riders
Gear choice and shortcut routes reward track study
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.