With respect, as much as I appreciate your misguided attempt to educate me, you just did not read my post. Take Hutball, for example.14 minutes long. Players come out at 3x your speed, flying around the arena. They die. They come out again at 3x your speed. You can't catch them. They do this for the full 14 minutes without break.
With respect, sounds like you are making things up, or grossly exaggerating.
If it's one opponent who you notice is always running at ridiculous speeds, it might be a speedhack. But this is exceedingly rare.
In 99.9% cases, it's a spell that you don't know / understand. If you don't provide a video of this, no one can ever tell you.