<blockquote><hr>
So you're saying that the special description is literally saying that the Tracking skill is figured into the ability?
<hr></blockquote>Not the skill level by itself, just the action of tracking someone from a distance away (although my testing has been very limited; the only thing I've observed is that without tracking someone I got something like +4 damage, while I got much more when I tracked someone from a screen away or more - I have not yet tried walking in circles around the target to see how much that helps).
Of course, it is really hard to track a good hider/stealther with only 20.1 (if not impossible), but the backstab ability does seem to actually become useful the rest of the time (but don't expect to use it more than once in any battle, the skill timer after using Hiding puts of the tracking attempt by 10 seconds).
I'll go do some more testing soon.
Update: here is my ongoing collected data... (37-42 base dmg)
<pre>Pig, 49, edge of screen
Rat, 48, edge of screen (~9 steps)
Rabbit, 47, started tracking at edge of screen but it moved to 5 steps away
Dog, 45, started tracking off-screen and walked 20 steps (it seems I may've been wrong about +12)
Bird, 54, started tracking off-screen and walked ~15 steps
Rat, 46, started tracking off-screen
Rat, 51, started tracking off-screen
Bird, 62, started tracking off-screen (went into backstab ASAP, attacked it on sight, seems +12 was not such a bad guess after all...)
Bird, 50, 6-7 steps away (backstab mode ASAP, attacked immediately)
Bird, 56, off-screen (backstab mode ASAP, et.c.)
Bird, 52, near screen edge (backstab mode ASAP, et.c.)
Rat, 44, off-screen but moved closer to me (and I attacked late)
Bird, 49, 5 steps away (the now usual treatment in all other regards)
Horse, 46, 1 screen away (15-20% physical resist)</pre>