head to head
vs
Left 4 DeadvsPac-Man 99
Left 4 Dead leans Execution (Twitch Chaos); Pac-Man 99 leans Execution (Practiced Mastery).
Left 4 DeadPac-Man 99
Axis by axis
Execution7 vs 7
Even - both lean on execution about the same.
Reads2 vs 2
Even - both lean on reads about the same.
Variance5 vs 4
Left 4 Dead leans harder on variance: AI Director randomizes hordes, items, and specials
Optimization5 vs 6
Pac-Man 99 leans harder on optimization: Ghost-train routing and target strategies have known best lines
Two games can score the same on an axis and still test it in very different ways - read each rationale, not just the number.