Hi! If I wanna do a speedrun of L4D2 with the version 2.0.0.0 how can I do it? Can change my version on Steam or I need to install a pirate version of the game or something?

Probably better to ask your question in the sub forum of Left 4 Dead 2: https://www.speedrun.com/l4d2

Oh, I didn't see it, thanks!!