Basically my question is: what unmodified speed stat is used in the formula after your Pokemon has been KO'd (It brings up 2 options: running and using another Pokemon)? Is it the speed of Pokemon that was KO'd or is it... something else?
Sorry if this is unanswerable, I'm curious.
It's the Pokémon that just fainted's speed. I just ran a test in X using 1 slower, lower level Pokemon, and one much faster Pokemon, and it was much easier to escape with the faster one one.