How efficient is the number screening generated in batch?

The screening efficiency is 50% to 60%. The number generated in batches has been generated in batches, and it needs to be screened effectively through a systematic random lottery process, which greatly increases the uncertainty of number screening, that is, it is impossible to be effective, thus generating the concept that the number generated in batches is efficient, which is proved to be about 50% or 60% by a large number of practices.