If you apply early, the probably nears 100% (if applicant fulfills all requirements). It fills up over a matter of months. An immigration lawyer will be able to tell you the chances at any given time.
Edit: Wait, is the lottery thing new? When I got my H-1B in 2013, my immigration lawyer gave me the above advice, i.e. that the process is first-come-first-serve.
Edit: Wait, is the lottery thing new? When I got my H-1B in 2013, my immigration lawyer gave me the above advice, i.e. that the process is first-come-first-serve.