head to head
Dirt Showdown asks more than Mario & Sonic at the Olympic Games Tokyo 2020, and the gap is optimization.

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

Execution · Twitch Chaos
A party collection of timing minigames designed to keep everyone competitive.
Dirt Showdown leans Execution (Practiced Mastery); Mario & Sonic at the Olympic Games Tokyo 2020 leans Execution (Twitch Chaos).
Dirt Showdown leans a little harder on execution, though the gap is small.
Dirt Showdown
Drifting, boosting and ramming need solid car control
Mario & Sonic at the Olympic Games Tokyo 2020
Button-timing and waggle minigames are the core test
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
Mario & Sonic at the Olympic Games Tokyo 2020
Light couch-PvP guessing in some head-to-head events
Mario & Sonic at the Olympic Games Tokyo 2020 leans a little harder on variance, though the gap is small.
Dirt Showdown
Crash physics and pack chaos add randomness
Mario & Sonic at the Olympic Games Tokyo 2020
Event RNG and party chaos level the field
Dirt Showdown leans clearly harder on optimization.
Dirt Showdown
Event types and boost routes are quickly learnable
Mario & Sonic at the Olympic Games Tokyo 2020
Each event has a shallow optimal technique to learn
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.