Check for gaps in IGI batch files

Hi everyone, I want to share something I discovered today. I found a gap in the records for Arandas in batch no. C602951 covering baptisms from 1768-1785 (film no. 279526). I had been looking for a relative born in 1785, but her name did not come up in searches at FamilySearch. I finally decided to enter the batch number in the search, and set the year to 1785. No records were returned (nor for 1784). When I set the year to 1783, it returned 145 results.
When I found this out, I opened the image file for that film and began to read each record, beginning where I thought she would be. I finally found her, Maria Vicente Roque Guzman Ornelas, baptized 2 Aug 1785, born 19 Jul 1785 in El Tule.
I will be going back to check other gaps in ancestral families. With the images available on line, this is easier than it used to be.
Hope this helps you with your familial gaps.