head to head
Tetris 99 asks more than Baku Baku, and the gap is execution.

Execution · Practiced Mastery
A competitive falling-block puzzle testing fast placement and combo chaining.

Execution · Pure Mechanics
Battle royale Tetris where raw stacking speed decides who outlasts 98 opponents.
Baku Baku leans Execution (Practiced Mastery); Tetris 99 leans Execution (Pure Mechanics).
Tetris 99 leans clearly harder on execution.
Baku Baku
Fast block placement under accelerating drop is the lead skill
Tetris 99
High-speed stacking and finesse define survival
Tetris 99 leans a little harder on reads, though the gap is small.
Baku Baku
Versus play has light read of opponent pace
Tetris 99
Targeting and badge timing against humans matter mid-match
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Baku Baku
Falling animal/food order is random but bounded
Tetris 99
Incoming garbage timing and piece sequence add chaos
Baku Baku leans a little harder on optimization, though the gap is small.
Baku Baku
Matching animals to food efficiently chains optimal combos
Tetris 99
Stacking theory and downstack efficiency are studied skills
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.