Is there any explaination why we dont have map files before december 2000?

[Valina35]

i mean theres .bat files in the wc mappack from 1999-2000 but the first actual map is december 18 2000, is there any explaination of this? like why would all maps from before that just get deleted with no trace by i assume valve when they where working on hl2

[t52]

These maps may have been made using GoldSrc

[MrDeclanMan2]

Okay, take this with a grain of salt, but i heard that supposedly Axel Gembe stopped really late through the entire download process, and that is hence why we don't have many assets from all the way back then like citizen.mdl or in this case, the 2000-1999 map files. I don't quite think this claim is true, as many files from the leak are from 1999 and 2000, so my theory is that Valve had different servers for the files, since they most likely use very different code.