What is lever throw and cable slack? In a guide for adjusting Avid BB7 mechanical road disc brakes, it said:


  Only use the barrel adjuster at the brake lever to adjust for cable slack. For lever throw, use the outboard adjustment knob. For brake pad wear adjustment, use both the inboard AND outboard knobs.


What is lever throw?

What is cable slack?



Which of these should I use to dictate how far I have to pull the levers to come to a dead stop?



For the BB7, it is recommended to have the inner (wheel-facing) pad about 2 times further from the rotor than the outer pad.
Lever throw is how much the lever moves in total.

Cable slack is how slack the cable is, ie. how much you have to pull before the brake pads start moving.

Park Tool says:


  Squeeze lever to test caliper brake. Adjust lever modulation setting by moving pads inward or outward from rotor by using both pad-adjusting knobs. To maintain the 2:1 ratio, turn the fixed pad-adjusting knob twice as many clicks as the moving pad-adjusting knob. For example, if a looser modulation is desired, turn the inner pad-adjusting knob counter-clockwise 4 clicks and the outer pad adjusting knob counterclockwise only 2 clicks.


The throw will be controlled by the total gap between pads and disc. For a short throw, a small gap, pads screwed a long way in, for a longer throw pads further apart, pads screwed out.