hunderslash

Note: 
The Stream ID is typically 11-12 digits long, and is divisible by 16. 
It can be found fairly easily using sites like sullygnome.com (better for 2015-2017 streams), and twitchtracker.com.
The VOD ID is 8-10 digits long, and sometimes shows up in clips-media-assets2.twitch.tv urls.
The Streamer ID is a numerical identifier for the streamer in question.

Format 1:
https://clips-media-assets2.twitch.tv/[Stream ID]-index-0000000000.mp4
These clips were created from May/June to August 2016.
The clip URLs increment with padding, so something like