“Horizontal and Vertical speed is .6 tiles/sec and diagonal is .84 tiles/sec. That's a big difference, especially to a script that can only see numbers. Changing your normal speed from .6 to .84 is a big difference, visually. It's just harder to see because it's diagonal.

Detecting speed hacks in general play(outside of closed environments like sparring) is practically impossible because of the variety of ways a player can move outside of just walking. It would take quite a lot of work to script it to exclude all these methods. Players jumping down cliffs, players being hit and flying back, changing levels, being warped but not changing levels so on and so forth. Not to mention hacks these days tend to exploit framerates instead of changing players position. Graal runs at 20fps(frames per second). Hack it to run at 40fps and suddenly your player is moving twice as fast as everyone else.

The problem aren't obvious speed hackers, it's the not-so-obvious ones. The ones that change their speed only slightly faster and toggle it constantly. Since Classic doesn't implement autobanning a staff has to see the warnings and check it out. If it's toggled or something they may just leave after a while of not seeing anything. Assuming a staff is on to see the warning at the time. ” - Dusty

The thread is closed so I couldn’t direct quote.