head to head
SpeedRunners asks more than Tetr.io, and the gap is reads.

Execution · Pure Mechanics
Momentum-perfect platform racing spiced with item mind games against humans.

Execution · Pure Mechanics
A competitive online stacker testing raw speed and versus stacking strategy.
SpeedRunners leans Execution (Pure Mechanics); Tetr.io leans Execution (Pure Mechanics).
Tetr.io leans a little harder on execution, though the gap is small.
SpeedRunners
Grapple swings and boost timing at full speed decide races
Tetr.io
Lightning-fast piece placement decides every match
SpeedRunners leans clearly harder on reads.
SpeedRunners
Timing item throws against human racers' habits wins exchanges
Tetr.io
Human opponents in versus can be anticipated somewhat
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
SpeedRunners
Item pickups add party-game chaos
Tetr.io
Bag randomizer is bounded and quickly mappable
Tetr.io leans a little harder on optimization, though the gap is small.
SpeedRunners
Optimal racing lines per track are learnable
Tetr.io
Stacking and garbage-management strategy underneath the speed
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.