I got this information from other website. NOTE: This applies to last year cases (FY 2014 )
"The earliest notifications in FY14 were premium-processing eMail receipts, which arrived on April 9, 2013. Even though the USCIS officially suspended premium processing timeframe guarantees for cap cases between April 1st and April 15th, some of the premium-processing cases, nonetheless, were acted upon promptly. The Murthy Law Firm even saw some cases approved by April 15,2013, for the last fiscal year.
By April 23, 2013, the Murthy Law Firm had received eMail receipts for the remaining cases filed under premium processing, as well as additional approval notices. Also by that time, hard copy receipt notices for H1B cases filed under standard, non-premium processing had begun to come in gradually. These receipts continued to arrive throughout April and into May.
In FY14, the USCIS began returning cases that had not been selected in the lottery on May 6, 2013. The packets containing these filings started to arrive via regular mail a few days later."
They have to cross check for names that have been entered more than once to improve probability of success and cross check a detected duplicate name against whether it was entered by same employer (not allowed unless job description is totally different) or a different employer (allowed).
All the best
Dr. Sandeep Shankar, Colorado Heights University, Denver, CO 80223, USA. www.chu.edu; sshankar@chu.edu