I just spent a bit of time with excel because I was bored.
http://puu.sh/8tun - Red indicates dead cop, blue indicates successful scum check.
Do note that it is huge (1000 cells). It takes into account a doctor, 1 cop, 1 roleblocker-mafia and 3 towns (assumed vanilla) but only goes up D2. It also assumes that the mafia will not roleblock and kill the same person.
To summarise;
No lynch:
- 14.4% chance to get a scum result without dying or being blocked (not on sheet, feel free to dispute if I am wrong)
- 16% chance to die (not on sheet, feel free to dispute)
Mislynch (aggregate);
-17.71% chance to die
- 6.34% of getting scum hit without being killed (from lynch and NK combined) or roleblocked.
If you do bother with the spreadsheet fiddle around with the numbers to get the individual scenario %'s but that's basically the baseline here.