This is another takeaway phone sourcing lesson from that prodigious and infamous RBC string about sourcing being dead:

Keith, you asked:
A question: approximately how many calls do you need to make to actually speak to 100 identified potential candidates, or conversely, how many identified potential candidates will you be able to speak to the first time out of 100 calls made with proper information?

Good questions. On the first one (approximately how many calls do you need to make to actually speak to 100 identified potential candidates) I'm not sure if you're asking me how many calls does a phone sourcer need to make to ID 100 potential candidates or how many calls does the recruiter need to make to reach the 100 identified potential candidates that the sourcer IDed (sounds like a Peter Picked Pickles, doesn't it?) Please clarify.

On your second question (how many identified potential candidates will you be able to speak to the first time out of 100 calls made with proper information) the key word in your query is "first". If you have 100 potential candidate names in front of you with the proper and correct information* when you sit down on a Tuesday, Wednesday or Thursday (notice I don't recommend Monday or Friday calling) morning whose titles/job skills fit the open position you need to fill, you will reach, on your first call-through of the list, maybe...
Get the answers here.