I judged in San Diego over the weekend. A couple of thoughts and observations;
I judged IPA and American Ales
About 90 IPA's were judged, About 20 advanced to a mini-BOS.
About 60 American Ales were judged, 15-18 advanced to mini-BOS
This is the first time I used the "Checklist" Scoresheets. I like them. At first I was hesitant, but I think they are effective. Talking to other judges, they had the same sentiment.
If you want to have better odds on advancing to the 2nd round, brew lagers, ciders, and meads. Most of them had less than 10 entries per category. I believe the Pilsner category only had 5 entries.
Quaff and the local organizers run a great 1st round. They get a lot of judges. For the IPA category, they had 22 judges and most if not all were BJCP certified. I don't think any judges judged more than 10 beers per flight.