The pyramid system doesn't exist anymore at any programs that I'm aware of. It's probably uneven because residents left or because they've added extra spots.

also, many schools have research slots that fill in as PGY-2's etc, residents may take a year off for personal reasons, programs can add spots,

have not heard of the pyramid coming back

hope this helps,

It can be because the RRC gave them an extra slot somewhere for whatever reason, or a resident was held back a year, or a resident had to take time off for personal reasons then rejoined, or perhaps some left the program. There are tons of reasons, but it can be something to ask if you interview there.

Definitely ask about residents leaving programs because that is a huge sign of problems, no matter what the reasons they give you may be.