Groundstop,
For now we bid lines of time for reserve. In the future we will shift to PBS for reserve. So for now you will get about 18 days of reserve, mostly in 4-6 day blocks with about 3-4 days off in between. These all start out as long call. The day prior the next days short call is assigned - this allows commuters to get into position. You can request a short call but its totally up to the schedulers as to which and how many pilots are on short call each day. Genrally they use historic data to figure out the requirements but I heard some guys claim it is more like vodoo. Anyhow 8 is the maximum number of short calls. I had 2 in December. Since I live within short call distance (normally considered to be about 2 hours from call to sign in) I sit short call at home. If your short call starts at 0300 so does your crew day. So if they call you at 0800 you already would be through 7 hours of your crew day (5 from on call plus 2 hour response). And at 1500 you would start 12 hours rest. All in all long call is much better - you can still drink beer, run a marathon, or go surfing. This is a basic explanation and does not cover every possible contingency.
Hope this answers your question.
Scoop