head to head
vs
Left 4 DeadvsRain World
Left 4 Dead leans Execution (Twitch Chaos); Rain World leans Variance (Twitch Chaos).
Left 4 DeadRain World
Axis by axis
Execution7 vs 6
Left 4 Dead leans harder on execution: Headshots, melee shoves, and special-infected reaction time
Reads2 vs 1
Left 4 Dead leans harder on reads: Versus mode adds human ambush mindgames
Variance5 vs 7
Rain World leans harder on variance: Creature placement and behavior shift unpredictably each cycle
Optimization5 vs 5
Even - both lean on optimization about the same.
Two games can score the same on an axis and still test it in very different ways - read each rationale, not just the number.