The problem is that that line is very blurry and thus that type of speedrunning doesn't really exist. And that's a huge, huge distinction you're making here.
Nearly every type of speedrun features glitches of some sort that developers didn't anticipate and thus not *intended*, simply because what's *intended* goes right out the window when you begin speedrunning. A huge part of speedrunning for example is the explotation of traversal mechanics and that includes exploiting mechanics for speed and to skip sections a developer couldn't possible have anticipated. You can take it to the extreme with the BLJ in Mario 64, but even just a slight increase in speed by moving in a certain way because of a coding error is technically a glitch and not really intended and make a huge difference over an entire run.
Sorry, for the rant and I get what you mean. Glitches that skip nearly the entire game or are outright credit warps aren't that interesting as speedruns (though their execution can be from a technical standpoint).
I get what you're saying and I get that there are instances where you can't make a clear distinction. It's just that it really started to get on my nerves when people jerking themselves or letting themselves be jerked off by people for claiming "World Record, 55s!" for a game that clearly could not have been finished in that time when you'd play it as it was designed. Again, from a technical point of view it is interesting but mainly because it lays bare how some of the things were programmed, not because of how the runner abuses them, that's the least interesting part.
But I agree with your blurry lines argument. Take Rollercoaster Tycoon 2, for example. It is very easy (and fast) to win each scenario by "abusing" certain mechanics. Are those glitches? No, they are just unintended consequences of mechanics that work together when you place certain rides. That, I would not classify as glitches. But using some sort of memory rewriting by using the safari zone glitch to trigger a buffer overflow in order to get access to certain memory blocks so you can rewrite them is a glitch, IMHO.
If you screw with values in memory without any specific mechanic in the game explicitly supporting it, I would call a glitch. The Rollercoaster Tycoon 2 example doesn't do that, you're never directly editing values in memory.
The most impressed I was with a speed run was that run where the guy basically learned patterns (and kept notes) of when and how random battles would occur. However, he also used to reset the console in order to set the seed for the random battles in a certain way and that I would call a glitch.
kotaku.com
where does the line get drawn and why?